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Sahelian countries are among the most vulnerable regions to climate change–related natural hazards, and Burkina Faso, located in the Sahelian zone of West Africa, is particularly exposed. This study analyzes a set of precipitation-based climate indices (RX1day, RX5day, SDII, CWD, R10mm, R20mm, R95pTOT, R99pTOT) and assesses the impact of climate change on the onset and cessation of the rainy season, as well as on intra-seasonal dry spells in Burkina Faso. We use CMIP6 climate model outputs downscaled to a 25 km spatial resolution. Projections are evaluated for the near future (2021–2050) and the far future (2071–2100), relative to the historical reference period (1981–2010), under two Shared Socioeconomic Pathways: SSP2-4.5 (intermediate) and SSP5-8.5 (high-emission, fossil-fuel–intensive). Model performance over the country is first assessed, then the spatiotemporal evolution of precipitation and extreme events is examined using ETCCDI (Expert Team on Climate Change Detection and Indices) metrics. We further investigate the evolution of maximum consecutive dry days (CDD) during the core rainy season (June–September), and the timing of rainy season onset and cessation. All analyses are carried out using Python and Climate Data Operators (CDO). The results indicate an increase in mean annual precipitation, exceeding 360 mm in the Sahelian zone, and a marked intensification of extreme rainfall events, with more heavy and very heavy rains that favor flooding, and destructive runoff. This emerging rainfall regime is associated with delayed onsets and cessations in many areas, earlier cessations in parts of the Sahelian zone, and longer intra-seasonal dry spells. Overall, total rainfall is projected to increase, but with improved onsets and poorer intra-seasonal distribution, leading to more frequent and damaging dry spells.