Projected Changes in the Characteristics of Dry and Wet Episodes over Côte d’Ivoire

This study analyses the persistence and frequency of multi-day dry and wet rainfall episodes over Côte d’Ivoire, which are quantified using CPC observations (1979–2022) and a 14-member Coordinated Regional Climate Downscaling Experiment (CORDEX)-Africa ensemble under RCP4.5 and RCP8.5. Rather than focusing solely on total rainfall, we quantify rainfall by duration and frequency of dry spells and wet episodes to capture duration-driven drought and flood risks. Historically, dry episodes last 8–15 days, with maximum annual dry spells of 25–40 days, while wet episodes persist for 3–6 days and occur 48 times per year. Projections show substantial changes in rainfall sequencing. Under RCP4.5, mean dry-episode durations increase by +1 to +2 days by mid-century and +2 to +4 days by late-century; under RCP8.5, increases reach +2 to +3 days and +3 to +6 days, respectively, with maximum dry-spell extensions of +15 to +25 days in northern regions. Wet episodes become 1–4 events per year, less frequent but lengthen by +1 to +4 days, especially along the coast under RCP8.5. These shifts suggest fewer but more persistent rainfall events, which heighten drought-related crop-water stress and multi-day flood accumulation risks. The results provide actionable insights for agriculture, hydrology and climate-risk planning by highlighting rainfall sequencing and persistence metrics not captured by traditional rainfall totals. This nuanced perspective enhances understanding of drought, flood accumulation, and agricultural risk under changing climate conditions.