TITLE:
Spatiotemporal Variability and Dominant Modes of Temperature Extremes over Africa during 1979-2024
AUTHORS:
Baraka Charles Bunini, Yi Fan, Elisia Hamisi Zobanya
KEYWORDS:
Temperature Extreme, Africa, Warming, Increasing Trends
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.2,
February
3,
2026
ABSTRACT: Temperature extremes are intensifying globally due to anthropogenic climate change, with Africa emerging as a hotspot of vulnerability despite contributing minimally to global emissions. Therefore, in this study we investigate the spatial and temporal variability of eight ETCCDI-based indices (TX90p, TN90p, TX10p, TN10p, TXx, TNx, TXn and TNn) over Africa during the period 1979-2024 using ERA5 reanalysis data. Empirical Orthogonal Function (EOF) analysis was applied to extract dominant modes of variability, and North test was used to assess the significance of each mode as well as we assessed the trend through 11-year moving average and standard deviation. Results show that the first EOF modes of warm-related indices such as TX90p, TN90p, TXx and TNx exhibit strong continent-wide warming patterns, while cold-related indices such as TX10p, TN10p, TNn, and TXn reveal declining cold extremes with more localized spatial signals. Temporal analysis of detrended principal components using 11-year moving averages and standard deviations highlights increasing trends and variability in warm extremes, particularly since the early 2000s, and a simultaneous reduction in cold extremes and their interannual fluctuations. Statistical testing (Mann-Kendall,
p<0.05
) confirms the significance of several of these trends, reinforcing the robustness of the observed changes. These findings underscore the growing climate risks associated with extreme temperatures in Africa and provide valuable insights for regional adaptation strategies, early warning system, and climate resilience planning.