Temperature–Precipitation Interactions in Upper Guinea: Evidence of Significant Climate Warming

Upper Guinea, located between the Sahelian and forest climates of West Africa, is particularly vulnerable to climate change. The region is experiencing an intensification of climatic extremes, characterized by increased precipitation variability and a gradual rise in temperatures, impacting ecosystems, water resources, and agriculture. This study analyzes temperature-precipitation interactions to better understand regional climate dynamics and anticipate hydrometeorological risks. Monthly satellite data from the CHIRTS (minimum and maximum temperatures) product (Climate Hazards InfraRed Temperature with Stations – Daily) and CHIRPS (precipitation) product (Climate Hazards Group InfraRed Precipitation with Station data) datasets covering 1986–2015 were used. Three methodological approaches were employed: monthly climatology, interannual trends, and Pearson correlation. Results show strong seasonality, with peak precipitation in August (~350 mm, ~29°C) and maximum temperatures reaching 38.5°C during the dry season. Precipitation exhibits interannual variability with no significant trend, while temperatures increase (+0.03°C per years). The trong correlation between minimum and maximum temperatures (r = 0.78) contrasts with weak negative correlations with rainfall (r ≈ -0.1), suggesting that the rise in temperatures is associated with a tendency toward decreasing rainfall. These highlight the complexity of local climate interactions and the urgent need to strengthen monitoring, seasonal forecasting, and agroclimatic adaptation.