Perceptions of Communities on Climate Change and Climate Variability in the Lake Chad Basin, Diffa Region

In a Sahelian context characterized by high hydroclimatic variability, the Diffa region is experiencing rainfall and temperature disturbances that are increasing the vulnerability of agropastoral systems. This study combines a survey of 234 households and the analysis of simulated climate data (1995–2025) to jointly assess perceptions of climate change and hydroclimatic dynamics. Climate variability is analysed using the SPI and SPEI indices, while trends and ruptures are examined using the Mann–Kendall and Petttt tests. The results show that agriculture dominates (> 60%), followed by livestock. Perceptions point to intense rainfall (11.2%), rising temperatures (10.6%) and irregular seasons. Climate indices reveal an intensification of extremes (TX90p = 41.88 °C; TN90 = 27.36 °C; R95p = 10.43 mm). The analysis of the SPI and SPEI indicates a high variability and a significant trend towards wetting (τ = 0.122 to 0.497; p < 0.001), with breaks around 2010–2018. Statistical analyses indicate negative effects of temperatures and positive effects of water conditions on livelihoods. These results underscore the need to strengthen tailored adaptation strategies.