Spatiotemporal Dynamics of Rainfall Variability and Extremes in Ethiopia Under CMIP6 Climate Scenarios

ABSTRACT This paper further investigates rainfall trends in Ethiopia, a climate‐sensitive country, with a focus on 10 of the best models in CMIP6, along with high‐resolution data from CHIRPS (1981–2022). Although many research studies exist, important research gaps are still left unanswered, especially in terms of spatial and temporal variations of extreme rainfall, particularly drought and flood hazards. This paper aims to bridge this knowledge gap with daily high‐resolution rainfall data, as well as bias‐corrected CMIP6 projections. The historical rainfall trend was quantified with a 1991–2020 baseline, whereas future projections were compared with a 1981–2014 baseline. The results indicate strong spatial variability in rainfall extremes across Ethiopia. Historically, northwestern, western and central Ethiopia show declining consecutive wet days (CWD; −0.2 days year −1 ), while the northeastern and eastern regions exhibit increasing CWD (+0.2 days year −1 ) alongside decreasing consecutive dry days (CDD; −0.4 days year −1 ). Maximum 1‐day precipitation (Rx1day) decreases across much of the northwest and northeast (up to −1.0 mm), contracting with localised increases in western Oromia and Southern Ethiopia (up to +1.5 mm). Heavy precipitation indices (R10, R20 and R25) increase in western and southwestern but decline in eastern and northeastern Ethiopia. Future projections under SSP2‐4.5 and SSP5‐8.5 scenarios show an intensification of these patterns, with increasing CDD across the northwest, west and southwest and enhanced wet spell duration CWD and rainfall intensity (SDII) over southern, northeastern, eastern and southeastern Ethiopia. By the end of the century, under the high‐emission SSP5‐8.5, western Ethiopia is projected to experience rainfall reductions of 15%–25% accompanied by increases of 25–45 consecutive dry days, heightening drought risk and threatening rain‐fed agriculture. In contrast, eastern regions are projected to experience 20%–30% increases in extreme rainfall, substantially elevating flood risk. These findings underscore the immediate need for locally targeted adaptation strategies, including region‐specific water‐resource management, climate‐resilient agriculture and flood‐risk reduction measures across Ethiopia.