Author(s)

Serge Dimitri Bazyomo¹, Lamboni Batablinlè^2,3,4, Ablam L. Afanou⁵, Yendoubé Lare³, Zakari Djibib³, Magolmeena Bannaa³, Lawin Agnidé Emmanuel^4,6

¹Laboratory of Thermal and Renewable Energies, Department of Physics, Unit of Training and Research on Exact and Applied Sciences, University Joseph KI-ZERBO, Ouagadougou, Burkina Faso.
²Department of Physics and Chemistry, Ecole Normale Supérieure of Atakpamé, Atakpamé, Togo.
³Laboratory of Solar Energy, University of Lomé, Lomé, Togo.
⁴Laboratory of Applied Hydrology, National Institute of Water, University of Abomey-Calavi, Cotonou, Benin.
⁵GTVD Laboratory (Waste Management, Treatment and Recovery), Faculty of Sciences, University of Lomé, BP, Lomé, Togo.
⁶International Laboratory of Physics of Atmospheric, Hydrology, Hydrometeorology, Climate Change and Energy, Cotonou, Benin.

This study combines historical analysis (1981-2024) and future projections (2020-2040) to assess seasonal rainfall patterns in Togo, focusing on the May–October rainy season. Using the multi-model mean from the CORDEX-Africa program, data were processed and analyzed in Python, with statistical tests applied to evaluate mean differences, relative changes, and their significance. Historical results reveal a single, well-defined rainy season peaking in August (230.92 mm on average), preceded and followed by an extended dry season from November to April with rainfall typically below 30 mm. Annual precipitation averages around 1500 mm but exhibits strong interannual variability influenced by ENSO events and the West African monsoon system. Spatial analysis shows August as the most challenging month to model accurately, with lower R² (0.79) and higher RMSE (41.57 mm) due to localized heavy rainfall. Projections for 2020-2040 indicate distinct north-south gradients, with significant increases in rainfall in northern regions during July-August and deficits in the south from July to October, highlighting contrasting flood and drought risks across the country.

Togo, Seasonal Rainfall, CORDEX-Africa, Climate Projections, Spatial Variability

Bazyomo, S. , Batablinlè, L. , Afanou, A. , Lare, Y. , Djibib, Z. , Bannaa, M. and Emmanuel, L. (2025) Decoding Togo’s Rainy Season: Historical Trends and Future Shifts under Variability and Changes Using CORDEX-Africa Models. Open Journal of Applied Sciences, 15, 2786-2799. doi: 10.4236/ojapps.2025.159186.