Heterogeneous trends of precipitation extremes in recent two decades over East Africa

East Africa is so vulnerable to the impacts of precipitation extremes which vary from frequent floods to prolonged droughts. However, systematic regional assessment of precipitation extremes across seasons has received little attention, and most previous studies of precipitation extremes have employed many indices and sparsely gauge observations giving marginalized details. In this study, we thus used three precipitation extreme indices to examine the intensity of the highest single-day rainfall record ( rx1day ), prevalence of very heavy rainfalls ( r30mm ), and persistence of successive wet days ( cwd ) at both annual and seasonal scales over two decades (1998–2018) with the Tropical Rainfall Measuring Mission (TRMM) Multi-Satellite Precipitation Analysis data. Results showed that the most intensive and frequent precipitation extremes are noticeable from January to May across areas extending from Madagascar to Tanzania coastal zone. These areas have also depicted patches of significant increasing trends in frequency, duration and intensity of precipitation extremes annually and seasonally. Besides, significant declines in frequency and intensity of precipitation extremes are depicted along areas extending from western Ethiopia to Congo-Uganda, especially in June-September season. October-December season exhibited higher interannual variability amounting to overall weak and less significant trends. The subregional assessment revealed northern sector intensive and frequent precipitation extremes featured more declining tendency while wetness duration averaged to increasing tendency implying the persistence of wet days backgrounding reducing severe events. The study unveils the higher susceptibility of the East Africa region to the widely observed hotspots of precipitation extremes posing threats to food security, water resource and human well-being. The region should consider upscaling irrigation schemes while also planning resilient and supportive infrastructures to withstand the upsurging precipitation extremes, especially along the coastal zone.