Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020)

Endalamaw Wende Wasihun

doi:doi:10.11648/j.ijees.20251004.14

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Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020)

Endalamaw Wende Wasihun^*

Published in International Journal of Energy and Environmental Science (Volume 10, Issue 4)

Received: 19 June 2025 Accepted: 16 July 2025 Published: 8 August 2025

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Abstract

This research assesses long-term trends in Jama District, South Wollo Zone, Ethiopia, of temperature and precipitation extremes using daily meteorological data (1981-2020) from Ethiopian Meteorology Institute (EMI). A total of 22 climate extreme indices—12 are for temperature and 10 are for precipitation—were computed following Expert Team on Climate Change Detection and Indices (ETCCDI) recommendations. The non-parametric Mann-Kendall test and Sen's slope estimator were applied to identify trends. Results show a statistically significant warming trend for several indices: rising hot days (SU25) by 3.936 days/year (p < 0.001), warm nights (TN90p) by 0.538 days/year (p = 0.001), and warm days (TX90p) by 0.597 days/year (p = 0.008). In contrast, cool nights (TN10p), cool days (TX10p), and cold spell duration (CSDI) decreased significantly by −0.541, −0.384, and −0.098 days/year, respectively (all p < 0.05), indicative of a sharp shift towards heat extremes. Precipitation indices were in overall positive but statistically not significant trends. Wet-day precipitation throughout the year (PRCPTOT) rose by 2.999 mm/year (p = 0.224), while heavy rainfall days (R10 and R20) rose by 0.170 and 0.076 days/year, respectively. Rainfall intensity (SDII) rose slightly by 0.027 mm/day/year. Extreme rainfall amounts (RX1day, RX5day) and wet/dry spell lengths (CWD, CDD) saw no changes. These findings confirm a clear warming signal and moderate rainfall variability, with important implications for agriculture, water resources, and climate adaptation planning in this vulnerable highland region.

Published in	International Journal of Energy and Environmental Science (Volume 10, Issue 4)
DOI	10.11648/j.ijees.20251004.14
Page(s)	92-102
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2025. Published by Science Publishing Group

Keywords

Climate Extremes Indices, Rainfall, Temperature, CDO, Mann-Kendall Test, Jama, South Wollo, Ethiopia

1. Introduction

Climate change and variability have become characteristic 21^st-century issues, particularly in nations like Ethiopia where agriculture, water, and livelihoods are highly climate-sensitive

[18, 19]

. East Africa has witnessed increasing frequencies and intensities of extreme weather events such as heatwaves, droughts, and heavy rainfall over the past few decades, posing significant risks to socio-economic systems

[24]

. These climate extremes are not only indicators of global climate change but also determinant drivers of local vulnerabilities, especially in rural and mountainous areas where adaptive capacity remains low.

Jama District, found in the South Wollo Zone of the Amhara Regional State, is an ideal example of this sensitivity because it possesses topographic complexity and rain-fed agricultural dependence

[17]

. The region has bimodal rainfall distribution and moderate thermal regime and is sensitive to temperature and rainfall variability, where agricultural and water supply systems are susceptible. In spite of the climate-sensitive characteristics of this highland ecosystem, limited work that investigates trends in temperature and precipitation extremes based on standardized indices at local levels is available. Much of the available literature is centered on larger geographic areas or country-level patterns

[4, 6]

, thus missing microclimatic differences and local effects.

To fill this gap, the present study provides an empirical assessment of temperature and precipitation extremes in Jama District for the period 1981-2020 using globally recognized indices developed by the Expert Team on Climate Change Detection and Indices (ETCCDI)

[20]

. By employing robust statistical methods such as the Mann-Kendall trend test and Sen's slope estimator

[13, 23]

, the study seeks to detect long-term trends in local climate extremes. These trends are important for regional adaptation planning, guiding sustainable resource management, and building the resilience of impacted communities.

This research aims to investigate shifting rainfall and temperature extreme trends in Jama District, South Wollo Zone, Ethiopia. By developing localized high-resolution data, the study supports evidence-based policymaking and pragmatic intervention in priority sectors like agriculture, water resource management, and disaster resilience and contributing to climate change studies.

2. Material and Methods

2.1. Study Area Description

Jama Districtis situated in the South Wollo Zone of the Amhara Regional State, Ethiopia. It is geographically located between latitude 10.158

°

to 10.594

°

North and longitude 39.054

°

to 39.420

°

East. The district shares boundaries like Legehida, Wereilu, Kelala, Efratana Gedem, Menz Gera midir, Menz Keya Gebriel, and Mimo Weremo. It is a highland region in Ethiopia with moderate heights and a seasonally changing climate.

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Figure 1. Map of the study area.

Climatically, Jama District is dominated by highly pronounced bimodal rainfall with a Kiremt peak. The thirty-year monthly climatological record indicates July and August as the wettest months having a mean rainfall of 274.1 mm and 292.4 mm respectively. The month November and December are the driest months with 6.4 mm and 6.6 mm mean precipitation.

Temperature regimes in Jama are relatively moderate. The highest mean temperatures range from 20.8°C in August to 25.6°C in May, and the lowest mean temperatures range from 5.5°C in December to 9.1°C in August. These relatively modest temperature regimes, along with the pattern of seasonal rainfall distribution, have extensive implications for agriculture, water supply, and livelihood as a whole in the region.

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Figure 2. Long-term average monthly rainfall, maximum temperature (Tmax), and minimum temperature (Tmin) of Jama.

2.2. Climate Data Source

This study was employed with daily precipitation and temperature (maximum and minimum) data for the period 1981 to 2020 to assess climate extreme trends in Jama district of South Wollo. This meteorological data were obtained from the Ethiopian Meteorology Institute (EMI) meteorological data delivery and dissemination desk. The data were processed using the Climate Data Tool (CDT) in R-packages, which includes components for quality control, homogenization, and index calculation.

2.3. Methods

2.3.1. Selection of Climate Extreme Indices

Joint Expert Team on Climate Change Detection and Indices (ETCCDI) defined 27 descriptive precipitation (11) and temperature (16) indices for measuring and describing climate change and variability

[20]

. Descriptive precipitation and temperature indices incorporate some extreme characteristics such as magnitude, intensity, and persistence

[10]

This study used 22 climate extreme indices (10 rainfall and 12 temperature extreme indices), which are computed using daily data. The indices were designed to identify the frequency, intensity, and duration of the extreme events. They include percentile-based indices (e.g., TX10p, TX90p, TN10p, TN90p, R95p, R99p), absolute indices (e.g., RX1day, RX5day, CDD, CWD), threshold indices (e.g., R10 mm, R20 mm), and duration indices (e.g., WSDI, CSDI). The entire list of indices and definitions is presented in Table 1 and Table 2.

Table 1. Rainfall extreme climate indices.

Index	Description	Definition	Units
PRCPTOT	Wet day precipitation	Annual total precipitation from wet days (> 1 mm)	mm
R95p	Very wet days	Annual total PRCP when RR > 95th percentile	mm
R99p	Extremely wet days	Annual total PRCP when RR > 99th percentile	mm
R10	Number of heavy precipitation days	Annual count of days when PRCP ≥ 10 mm	days
R20	Very heavy precipitation	Annual count of days when PR ≥ 20 mm	Days
SDII	Simple daily intensity index	Annual total precipitation divided by the number of wet days (defined as PR ≥ 1.0 mm) in the year	mm per day
CDD	Consecutive dry days	Maximum number of consecutive days with RR < 1 mm	Days
CWD	Consecutive wet days	Maximum number of consecutive days with RR ≥ 1 mm	Days
RX1day	Max 1-day precipitation amount	Monthly maximum 1-day precipitation	mm
Rx5day	Max 5-day precipitation amount	Monthly maximum 5-day precipitation	mm

Table 2. Temperature extreme climate indices.

Index	Description	Definition	Units
SU25	Hot days	Annual count when TX>25℃	Days
TN10p	Cool nights	Percentage of days when TN < 10th percentile	Days
TX10p	Cool days	Percentage of days when TX < 10th percentile	Days
TN90p	Warm night	Percentage of days when TN > 90th percentile	Days
TX90p	Warm days	Percentage of days when TX > 90th percentile	Days
WSDI	Warm spell duration indicator	Annual count of days with at least 6 consecutive days when TX > 90th percentile	Days
CSDI	Cold spell duration indicator	Annual count of days with at least 6 consecutive days when TN < 10th percentile	Days
DTR	Diurnal temperature range	Monthly mean difference between TX and TN	˚C
TXn	Min Tmax	Monthly minimum value of daily maximum temperature	˚C
TXx	Max Tmax	Monthly maximum value of daily maximum temperature	˚C
TNn	Min Tmin	Monthly minimum value of daily minimum temperature	˚C
TNx	Max Tmin	Monthly maximum value of daily minimum temperature	˚C

2.3.2. Trend and Significance Tests

Climate Data Tool (CDT) R packages

[1]

were used for pre-processing input data, such as quality control, data homogenization, and index calculation. We used CDT to compute the ETCCDI indices (Table 1 and Table 2) from 1981-2020 daily precipitation and temperature (maximum and minimum) ENACTS data.

Mann-Kendall (MK) long-term trend statistical test was applied to identify the trend in all the extreme temperature and precipitation indexes. Non-parametric MK trend Mann

[13]

and its subsequent modification Kendal

[12]

has been extensively used for the identification of monotonic trends in the environmental and hydro-climatologically global data series

[5]

. The linear trend of each time series was calculated using Kendall's tau function at a significance level of 0.05.

3. Result and Discussion

3.1. Trends in Extreme Rainfall Indices

Ten extreme rainfall indices were computed for Jama District to analyze trends in precipitation extremes and their significance at a statistical level (Table 3). Indices were taken for analysis such as total precipitation (PRCPTOT), percentiles of extreme precipitation (R95p, R99p), frequency of heavy and very heavy precipitation occurrence (R10, R20), intensity of precipitation (SDII), and duration-based parameters such as consecutive wet and dry days (CDD, CWD), and maximum 1-day and 5-day precipitation values (RX1day, RX5day) (Table 3).

Overall, all indices showed positive but statistically insignificant trends at 95% confidence level. Annual wet-day precipitation (PRCPTOT) experienced a positive slope of 2.999 mm/year (p = 0.224), signifying the overall increase in rainfall over time slowly. This was supported by findings from the Central Highlands of Ethiopia, Moges & Bhat

[19]

, who also reported increasing but not significant trends in annual rainfall across different stations. Similar results were found in a study over Addis Ababa. Mekonnen et al.

[15]

, where most rainfall indices, including PRCPTOT, exhibited upward trends that were not statistically significant, reflecting a broader pattern of slowly increasing rainfall across highland areas of Ethiopia. Whereas the study conducted by Tashebo and Mekonnen

[26]

on trends in daily temperature and precipitation extremes over Dire-Dawa (1980-2018) contradict to this study findings. On this study, the annual trend PRCPTOT showed a decrement trend of -1.626 mm/year.

The frequency of heavy (R10) and very heavy (R20) rainy days (Figure 3) indicated small increases (0.170 and 0.076 days/year, respectively), though statistically not significant. Southern Ethiopia witnessed similar trends of increased R10 and R20. According to Mengistu et al.

[16]

suggest an augmentation of regional signal of rainfall extremes, likely because of alteration in the season's rainfall distribution.

Conversely, the heavy rainfall indices R95p and R99p, which are very wet and extremely wet days, showed very weak or negative trends (0.493 mm/year and -0.207 mm/year, respectively), both statistically insignificant. These results suggest that while heavy rain days are increasing slightly, the most extreme events are not increasing in frequency or intensity, in agreement with the result of Sleshi and Camberlin

[22]

who found no significant increase in extreme daily rainfall in the northeastern Ethiopian highlands.

The Simple Daily Intensity Index (SDII) showed a slight increment of 0.027 mm/day/year, which supports the idea that the intensity of rainfall per wet day may be on the rise. This could suggest a possibility for more intense storm events, consistent with East African climate model projections

[8]

Regarding duration of dry and wet spells, Consecutive Dry Days (CDD) and Consecutive Wet Days (CWD) trends were both positive (0.206 and 0.129 days/year, respectively), exhibiting no visible dominance of drying or wetting spells. Jury

[9]

also noted a similar lack of trend in East African drought frequency, which was highly variable in space and time. Similar studies conducted by Mekonnen & Ayele

[15]

and Tashebo

[25]

also indicated a positive Consecutive Dry Days (CDD) and Consecutive Wet Days (CWD) trends over Addis Ababa, Ethiopia.

The extreme precipitation indices RX1day and RX5day also indicated minimal changes (0.076 and 0.133 mm/year, respectively) with no statistical significance. The results are contrary to those from near district of Wereilu where statistically significant rising trends in RX1day by 1.9 mm/decade and Rx5day by 9.6 mm/decade were established by Hailu et al.

[7]

, which indicate possible spatial variability in the extreme rainfall mechanisms with in the country.

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Figure 3. Average annual trends of extreme precipitation indices for PRCPTOT, SDII, Rx1day, Rx5day, R10mm, R20mm, CDD, CWD, R95p, and R99p from 1981 to 2020.

Table 3. Trend analysis of the ten rainfall extreme climate indices for Jama District, South Wollo.

Index	Description	Units	Slope	P-Value
PRCPTOT	Wet day precipitation	mm	2.999	0.224
R95p	Very wet days	mm	0.493	0.777
R99p	Extremely wet days	mm	-0.207	0.783
R10	Number of heavy precipitation days	days	0.170	0.157
R20	Very heavy precipitation	Days	0.076	0.347
SDII	Simple daily intensity index	mm per day	0.027	0.349
CDD	Consecutive dry days	Days	0.206	0.449
CWD	Consecutive wet days	Days	0.129	0.363
RX1day	Max 1-day precipitation amount	mm	0.076	0.632
Rx5day	Max 5-day precipitation amount	mm	0.133	0.821

3.2. Trends in Extremes Temperature Indices

Analysis of twelve temperature-based extreme climate indices of study area reveals statistically significant shifts in some characteristics of extremes of temperature indicating an unambiguous warming trend for the area (Table 4).

SU25, representing days with more than 25°C maximum temperature, has risen by a large magnitude of 3.936 annually (p = 0.000) per year, hence indicating an increase in heat intensity at a fast rate. Findings from Upper Blue Nile Basin of Ethiopiaon the study of changes in observed rainfall and temperature extremes also agree with this indication, Ali Mohammed et al.

[2]

documented significant rises in SU25. Similar rises have been observed across the Horn of Africa too, suggesting a regional trend towards warming

[6]

Similarly, warm temperature extremes are also evidenced in the positive trends of warm nights (TN90p: +0.538 days/year, p = 0.001) and warm days (TX90p: +0.597 days/year, p = 0.008). These indicate not only heightened daytime heat but also decreased nighttime cooling. As in the Ethiopian Rift Valley and central highlands

[3]

, such warm day and night increases have been reported due to anthropogenic climate change and land use changes. The study conducted by MEKONNEN et al.

[14]

also indicated an increasing trend in warm nights (TN90P) at a significance level of 5% on the study area of Addis Ababa.

At the same time, cool temperature extremes are in decline. Cool night (TN10p) and cool day (TX10p) indices both exhibit significant negative trends (−0.541 and −0.384 days/year, respectively), with p-values < 0.05. This agrees with global findings of the IPCC Sixth Assessment Report that state that cold extremes are declining in magnitude and frequency at a global level

[8]

. Likewise, the cold spell duration index (CSDI) decreased considerably (−0.098 days/year, p = 0.039), which also confirms the trend of warming in nighttime temperatures.

Warm spell duration index (WSDI) showed a non-significant rising trend (+0.019 days/year) relative to which suggests higher frequency within the number of warm days, not strongly evident, instead of longer persistence over consecutive days. Why this might be is perhaps due to inter-annual variability or local climatic buffering as investigated by

[11]

in a heatwave evaluation of Ethiopia.

Other measures of temperature also confirm warming. Daily minimum temperature (TNn and TXn) and daily maximum temperature (TXx and TNx) minimum and maximum values all indicate increasing trends, with TNn (+0.087°C/year, p = 0.006) and TXx (+0.096°C/year, p = 0.024) being statistically significant (Figure 4). All these are expected outcomes with the overall trend of warming observed in East Africa where Tmin has increased at a higher rate than Tmax, especially over highlands

[4]

Remarkably, the Diurnal Temperature Range (DTR) shows a non-significant but decreasing tendency (−0.008°C/year), meaning that nighttime temperature may be increasing more rapidly than daytime temperature. A decreasing DTR has been observed widely in tropical regions and is associated with increased atmospheric moisture and urban heat island effects

[21]

Table 4. Trend analysis of the twelve extreme climate indices of temperature for Jama Districtof South Wollo.

Index	Description	Units	Slope	P-Value
SU25	Hot days	Days	3.936	0.000
TN10p	Cool nights	Days	-0.541	0.030
TX10p	Cool days	Days	-0.384	0.000
TN90p	Warm night	Days	0.538	0.001
TX90p	Warm days	Days	0.597	0.008
WSDI	Warm spell duration indicator	Days	0.019	0.433
CSDI	Cold spell duration indicator	Days	-0.098	0.039
DTR	Diurnal temperature range	˚C	-0.008	0.750
TXn	Min Tmax	˚C	0.053	0.064
TXx	Max Tmax	˚C	0.096	0.024
TNn	Min Tmin	˚C	0.087	0.006
TNx	Max Tmin	˚C	0.043	0.388

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Figure 4. Average annual trends of extreme temperature indices for SU, DTR, CSDI, WSDI, TX10p, TX90p, TXn, TXx, TN10p, TN90p, TNn and TNx from 1981 to 2020.

4. Conclusion

This study provided a comprehensive assessment of climate extreme trends in Jama District using 40 years (1981-2020) of daily temperature and precipitation records and the standardized ETCCDI indices. The results show unequivocal evidence of warming in the region, with statistically significant increasing trends in hot days (SU25), warm nights (TN90p), and warm days (TX90p), and corresponding significant decreasing trends in cold extremes (TN10p, TX10p, and CSDI). These shifts are a step in the direction of more frequent and intense heat episodes with consequences for agriculture, water supply, and public health.

In contrast, trends in precipitation extremes were positive but not statistically significant. While there was a slight increase in total rainfall, amount and in the number of heavy and very heavy rainfall days (R10 and R20), extreme wet events (R95p and R99p) and intensity indices such as RX1day and RX5day did not show strong increasing trends. This is suggestive of rainfall maybe increasing in intensity to a certain degree, but the most severe precipitation events are yet to escalate in frequency and severity. The lack of detectable changes in the length of dry and wet spells (CDD and CWD) also suggests a comparatively stable, even though variable, rainfall regime.

Overall, the findings project an intensifying thermal stress in Jama District, which has the potential to enhance local vulnerability, especially in rain-fed agriculture and water resource management sectors. The absence of statistically significant precipitation extremes can offer some short-term relief, but the continuity of the warming trend necessitates urgent attention towards adaptation strategies and early warning systems. These findings must be integrated into climate-resilient development plans by local policymakers and planners to enhance the region's capacity to adapt to evolving climate risks.

Abbreviations

CDD	Consecutive Dry Days
CDT	Climate Data Tool
CSDI	Cold Spell Duration Indicator
CWD	Consecutive Wet Days
DTR	Diurnal Temperature Range
EMI	Ethiopian Meteorology Institute
ENACT	Enhancing National Climate Service
ETCCDI	Expert Team on Climate Change Detection and Indices
IPCC	Intergovernmental Panel on Climate Change
MK	Mann-Kendall
PRCPTOT	Precipitation Total
SDII	Simple Daily Intensity Index
WSDI	Warm Spell Duration Indicator

Acknowledgments

The author would like to thanks Ethiopian Meteorology Institute (EMI) of data deliver and dissemination desks to provide a significant meteorological data for this research study.

Author Contributions

Endalamaw Wende Wasihun is the sole author. The author read and approved the final manuscript.

Data Availability Statement

Meteorological data for this study were obtained from Ethiopia Meteorological Institute, Addis Ababa.

Funding

For the study presented, the author received no support from any organization.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Alexander, L., & Herold, N. (2016). ClimPACT2: Indices and software.
[2]	Ali Mohammed, J., Gashaw, T., Worku Tefera, G., Dile, Y. T., Worqlul, A. W., & Addisu, S. (2022). Changes in observed rainfall and temperature extremes in the Upper Blue NileBasin of Ethiopia. Weather and Climate Extremes, 37(June), 100468. https://doi.org/10.1016/j.wace.2022.100468
[3]	Asfaw, A., Simane, B., Hassen, A., & Bantider, A. (2018). Variability and time series trend analysis of rainfall and temperature in northcentral Ethiopia: A case study in Woleka sub-basin. Weather and Climate Extremes, 19, 29-41.
[4]	Endris, H. S., Omondi, P., Jain, S., Lennard, C., Hewitson, B., Chang’a, L., Awange, J. L., Dosio, A., Ketiem, P., & Nikulin, G. (2013). Assessment of the performance of CORDEX regional climate models in simulating East African rainfall. Journal of Climate, 26(21), 8453-8475.
[5]	Garba, H., & Udokpoh, U. U. (2023). Analysis of trend in meteorological and hydrological time-series using Mann-Kendall and Sen’s slope estimator statistical test in Akwa Ibom state, Nigeria. International Journal of Environment and Climate Change, 13(10), 1017-1035.
[6]	Gebrechorkos, S. H., Hülsmann, S., & Bernhofer, C. (2019). Regional climate projections for impact assessment studies in East Africa. Environmental Research Letters, 14(4). https://doi.org/10.1088/1748-9326/ab055a
[7]	Hailu, D., Woldetsadik, M., & Ayal, D. Y. (2025). Changes in extreme rainfall indices in Wereilu district, northeastern Ethiopian highlands, using innovative trend analysis. Discover Applied Sciences, 7(3). https://doi.org/10.1007/s42452-025-06657-3
[8]	Intergovernmental Panel on Climate Change (IPCC). (2023). Climate Change 2021 - The Physical Science Basis. In Climate Change 2021 - The Physical Science Basis. https://doi.org/10.1017/9781009157896
[9]	Jury, M. R. (2011). Long-term variability and trends in the Caribbean Sea. International Journal of Oceanography, 2011(1), 465810.
[10]	Karl, D. M. (1999). A sea of change: biogeochemical variability in the North Pacific Subtropical Gyre. Ecosystems, 2, 181-214.
[11]	Kassie, B. T. (2014). Climate variability and change in Ethiopia: Exploring impacts and adaptation options for cereal production. Wageningen University and Research.
[12]	Kendall, K. (1975). Thin-film peeling-the elastic term. Journal of Physics D: Applied Physics, 8(13), 1449.
[13]	Mann, H. B. (1945). Nonparametric tests against trend. Econometrica: Journal of the Econometric Society, 245-259.
[14]	MEKONNEN, et al. (2024). Trends in rainfall and temperature extremes during 1954-2019 in Addis Ababa, Ethiopia. Journal of Agrometeorology, 6(1), 5-9.
[15]	Mekonnen, E. F., Assefa, M. A., & Ayele, A. G. (2024). Trends of Extreme Temperature and Rainfall Indices for Addis Ababa City, Ethiopia. Journal of Environmental Science and Agricultural Research.
[16]	Mengistu, D., Bewket, W., Dosio, A., & Panitz, H.-J. (2021). Climate change impacts on water resources in the upper blue nile (Abay) river basin, ethiopia. Journal of Hydrology, 592, 125614.
[17]	Meressa, A. M., & Bantie, L. (2024). The impacts of climate change on peasant’s crop production in major crop producing zones in Ethiopia. Discover Sustainability, 5(1). https://doi.org/10.1007/s43621-024-00628-1
[18]	Mewded, M., Abebe, A., Tilahun, S., & Agide, Z. (2022). Climate variability and trends in the Endorheic Lake Hayk basin: implications for Lake Hayk water level changes in the lake basin, Ethiopia. Environmental Systems Research, 11(1), 1-17.
[19]	Moges, D. M., & Bhat, H. G. (2021). Climate change and its implications for rainfed agriculture in Ethiopia. Journal of Water and Climate Change, 12(4), 1229-1244.
[20]	Peterson, A. T., Sánchez-Cordero, V., Soberón, J., Bartley, J., Buddemeier, R. W., & Navarro-Sigüenza, A. G. (2001). Effects of global climate change on geographic distributions of Mexican Cracidae. Ecological Modelling, 144(1), 21-30.
[21]	Pyrgou, A., Santamouris, M., & Livada, I. (2019). Spatiotemporal analysis of diurnal temperature range: Effect of urbanization, cloud cover, solar radiation, and precipitation. Climate, 7(7), 1-13. https://doi.org/10.3390/cli7070089
[22]	Seleshi, Y., & Camberlin, P. (2006). Recent changes in dry spell and extreme rainfall events in Ethiopia. Theoretical and Applied Climatology, 83, 181-191.
[23]	Sen, P. K. (1968). Estimates of the Regression Coefficient Based on Kendall’s Tau. Journal of the American Statistical Association, 63(324), 1379-1389. https://doi.org/10.1080/01621459.1968.10480934
[24]	Siabi, E. K., Awafo, E. A., Kabo-bah, A. T., Derkyi, N. S. A., Akpoti, K., Mortey, E. M., & Yazdanie, M. (2023). Assessment of Shared Socioeconomic Pathway (SSP) climate scenarios and its impacts on the Greater Accra region. Urban Climate, 49. https://doi.org/10.1016/j.uclim.2023.101432
[25]	Tashebo, G. B. (2022). Analysis of Trend in Extreme Temperature and Rainfall over Addis Ababa City, Analysis of Trend in Extreme Temperature and Rainfall over Addis Ababa City, the Case of Bole Meteorological Station Gezahegn Bekele Tashebo. July.
[26]	Tashebo, G. B., & Mekonnen, E. F. (2021). Trends in Daily Temperature and Precipitation Extremes over Dire-Dawa, 1980-2018. Journal of Environment and Earth Science, October, 5-12. https://doi.org/10.7176/jees/11-9-03

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Wasihun, E. W. (2025). Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020). International Journal of Energy and Environmental Science, 10(4), 92-102. https://doi.org/10.11648/j.ijees.20251004.14

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Wasihun, E. W. Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020). Int. J. Energy Environ. Sci. 2025, 10(4), 92-102. doi: 10.11648/j.ijees.20251004.14

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AMA Style

Wasihun EW. Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020). Int J Energy Environ Sci. 2025;10(4):92-102. doi: 10.11648/j.ijees.20251004.14

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@article{10.11648/j.ijees.20251004.14,
  author = {Endalamaw Wende Wasihun},
  title = {Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020)
},
  journal = {International Journal of Energy and Environmental Science},
  volume = {10},
  number = {4},
  pages = {92-102},
  doi = {10.11648/j.ijees.20251004.14},
  url = {https://doi.org/10.11648/j.ijees.20251004.14},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijees.20251004.14},
  abstract = {This research assesses long-term trends in Jama District, South Wollo Zone, Ethiopia, of temperature and precipitation extremes using daily meteorological data (1981-2020) from Ethiopian Meteorology Institute (EMI). A total of 22 climate extreme indices—12 are for temperature and 10 are for precipitation—were computed following Expert Team on Climate Change Detection and Indices (ETCCDI) recommendations. The non-parametric Mann-Kendall test and Sen's slope estimator were applied to identify trends. Results show a statistically significant warming trend for several indices: rising hot days (SU25) by 3.936 days/year (p < 0.001), warm nights (TN90p) by 0.538 days/year (p = 0.001), and warm days (TX90p) by 0.597 days/year (p = 0.008). In contrast, cool nights (TN10p), cool days (TX10p), and cold spell duration (CSDI) decreased significantly by −0.541, −0.384, and −0.098 days/year, respectively (all p < 0.05), indicative of a sharp shift towards heat extremes. Precipitation indices were in overall positive but statistically not significant trends. Wet-day precipitation throughout the year (PRCPTOT) rose by 2.999 mm/year (p = 0.224), while heavy rainfall days (R10 and R20) rose by 0.170 and 0.076 days/year, respectively. Rainfall intensity (SDII) rose slightly by 0.027 mm/day/year. Extreme rainfall amounts (RX1day, RX5day) and wet/dry spell lengths (CWD, CDD) saw no changes. These findings confirm a clear warming signal and moderate rainfall variability, with important implications for agriculture, water resources, and climate adaptation planning in this vulnerable highland region.},
 year = {2025}
}

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TY  - JOUR
T1  - Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020)

AU  - Endalamaw Wende Wasihun
Y1  - 2025/08/08
PY  - 2025
N1  - https://doi.org/10.11648/j.ijees.20251004.14
DO  - 10.11648/j.ijees.20251004.14
T2  - International Journal of Energy and Environmental Science
JF  - International Journal of Energy and Environmental Science
JO  - International Journal of Energy and Environmental Science
SP  - 92
EP  - 102
PB  - Science Publishing Group
SN  - 2578-9546
UR  - https://doi.org/10.11648/j.ijees.20251004.14
AB  - This research assesses long-term trends in Jama District, South Wollo Zone, Ethiopia, of temperature and precipitation extremes using daily meteorological data (1981-2020) from Ethiopian Meteorology Institute (EMI). A total of 22 climate extreme indices—12 are for temperature and 10 are for precipitation—were computed following Expert Team on Climate Change Detection and Indices (ETCCDI) recommendations. The non-parametric Mann-Kendall test and Sen's slope estimator were applied to identify trends. Results show a statistically significant warming trend for several indices: rising hot days (SU25) by 3.936 days/year (p < 0.001), warm nights (TN90p) by 0.538 days/year (p = 0.001), and warm days (TX90p) by 0.597 days/year (p = 0.008). In contrast, cool nights (TN10p), cool days (TX10p), and cold spell duration (CSDI) decreased significantly by −0.541, −0.384, and −0.098 days/year, respectively (all p < 0.05), indicative of a sharp shift towards heat extremes. Precipitation indices were in overall positive but statistically not significant trends. Wet-day precipitation throughout the year (PRCPTOT) rose by 2.999 mm/year (p = 0.224), while heavy rainfall days (R10 and R20) rose by 0.170 and 0.076 days/year, respectively. Rainfall intensity (SDII) rose slightly by 0.027 mm/day/year. Extreme rainfall amounts (RX1day, RX5day) and wet/dry spell lengths (CWD, CDD) saw no changes. These findings confirm a clear warming signal and moderate rainfall variability, with important implications for agriculture, water resources, and climate adaptation planning in this vulnerable highland region.
VL  - 10
IS  - 4
ER  -

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Endalamaw Wende Wasihun

Development Meteorology, Ethiopian Meteorology Institute, Kombolcha, Ethiopia

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Wasihun, E. W. (2025). Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020). International Journal of Energy and Environmental Science, 10(4), 92-102. https://doi.org/10.11648/j.ijees.20251004.14

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ACS Style

Wasihun, E. W. Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020). Int. J. Energy Environ. Sci. 2025, 10(4), 92-102. doi: 10.11648/j.ijees.20251004.14

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AMA Style

Wasihun EW. Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020). Int J Energy Environ Sci. 2025;10(4):92-102. doi: 10.11648/j.ijees.20251004.14

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@article{10.11648/j.ijees.20251004.14,
  author = {Endalamaw Wende Wasihun},
  title = {Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020)
},
  journal = {International Journal of Energy and Environmental Science},
  volume = {10},
  number = {4},
  pages = {92-102},
  doi = {10.11648/j.ijees.20251004.14},
  url = {https://doi.org/10.11648/j.ijees.20251004.14},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijees.20251004.14},
  abstract = {This research assesses long-term trends in Jama District, South Wollo Zone, Ethiopia, of temperature and precipitation extremes using daily meteorological data (1981-2020) from Ethiopian Meteorology Institute (EMI). A total of 22 climate extreme indices—12 are for temperature and 10 are for precipitation—were computed following Expert Team on Climate Change Detection and Indices (ETCCDI) recommendations. The non-parametric Mann-Kendall test and Sen's slope estimator were applied to identify trends. Results show a statistically significant warming trend for several indices: rising hot days (SU25) by 3.936 days/year (p < 0.001), warm nights (TN90p) by 0.538 days/year (p = 0.001), and warm days (TX90p) by 0.597 days/year (p = 0.008). In contrast, cool nights (TN10p), cool days (TX10p), and cold spell duration (CSDI) decreased significantly by −0.541, −0.384, and −0.098 days/year, respectively (all p < 0.05), indicative of a sharp shift towards heat extremes. Precipitation indices were in overall positive but statistically not significant trends. Wet-day precipitation throughout the year (PRCPTOT) rose by 2.999 mm/year (p = 0.224), while heavy rainfall days (R10 and R20) rose by 0.170 and 0.076 days/year, respectively. Rainfall intensity (SDII) rose slightly by 0.027 mm/day/year. Extreme rainfall amounts (RX1day, RX5day) and wet/dry spell lengths (CWD, CDD) saw no changes. These findings confirm a clear warming signal and moderate rainfall variability, with important implications for agriculture, water resources, and climate adaptation planning in this vulnerable highland region.},
 year = {2025}
}

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TY  - JOUR
T1  - Evidence of Warming and Rainfall Variability in a Highland Region of Ethiopia: Climate Extremes in Jama District (1981 to 2020)

AU  - Endalamaw Wende Wasihun
Y1  - 2025/08/08
PY  - 2025
N1  - https://doi.org/10.11648/j.ijees.20251004.14
DO  - 10.11648/j.ijees.20251004.14
T2  - International Journal of Energy and Environmental Science
JF  - International Journal of Energy and Environmental Science
JO  - International Journal of Energy and Environmental Science
SP  - 92
EP  - 102
PB  - Science Publishing Group
SN  - 2578-9546
UR  - https://doi.org/10.11648/j.ijees.20251004.14
AB  - This research assesses long-term trends in Jama District, South Wollo Zone, Ethiopia, of temperature and precipitation extremes using daily meteorological data (1981-2020) from Ethiopian Meteorology Institute (EMI). A total of 22 climate extreme indices—12 are for temperature and 10 are for precipitation—were computed following Expert Team on Climate Change Detection and Indices (ETCCDI) recommendations. The non-parametric Mann-Kendall test and Sen's slope estimator were applied to identify trends. Results show a statistically significant warming trend for several indices: rising hot days (SU25) by 3.936 days/year (p < 0.001), warm nights (TN90p) by 0.538 days/year (p = 0.001), and warm days (TX90p) by 0.597 days/year (p = 0.008). In contrast, cool nights (TN10p), cool days (TX10p), and cold spell duration (CSDI) decreased significantly by −0.541, −0.384, and −0.098 days/year, respectively (all p < 0.05), indicative of a sharp shift towards heat extremes. Precipitation indices were in overall positive but statistically not significant trends. Wet-day precipitation throughout the year (PRCPTOT) rose by 2.999 mm/year (p = 0.224), while heavy rainfall days (R10 and R20) rose by 0.170 and 0.076 days/year, respectively. Rainfall intensity (SDII) rose slightly by 0.027 mm/day/year. Extreme rainfall amounts (RX1day, RX5day) and wet/dry spell lengths (CWD, CDD) saw no changes. These findings confirm a clear warming signal and moderate rainfall variability, with important implications for agriculture, water resources, and climate adaptation planning in this vulnerable highland region.
VL  - 10
IS  - 4
ER  -

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