Meteorological drought trends in Burkina Faso (1991–2023): A monthly and seasonal rainfall anomaly index analysis

This article analyzes monthly and seasonal spatial trends in drought within Burkina Faso using the Rainfall Anomaly Index (RAI). Rainfall data from the Burkina National Meteorological Agency (1991–2023) were processed using the R package ‘precinctcon’ and hydroTSM. Trends were then evaluated using Spearman’s Rho (SR) tests and Inverse Distance Weighting (IDW) interpolation. The results demonstrated a seasonally differentiated distribution of droughts. While drought dominates the pre-wet season; a distinct wet phase occurs during the peak rainy months of July and August. In contrast, the post-wet season, exhibits fluctuating wet and drought periods. RAI values reflect high inter-seasonal variability, showing that rainfall is concentrated into only a few months. This exposes different regions of Burkina Faso to greater risks of drought. This concentration increases drought risk across various regions, creating significant challenges for farmers during the shoulder seasons and posing a major threat to food security for Burkina Faso’s rural populations.