Investigating the Relationship Between Sea Surface Temperature and Rainfall Over Coastal Ogun State

Sea surface temperature (SST) anomalies in the Gulf of Guinea exert a well-documented influence on West African rainfall variability, yet local-scale studies documenting this teleconnection over specific Nigerian coastal zones remain limited. This study investigates the statistical relationship between Gulf of Guinea SST anomalies and monthly rainfall totals over coastal Ogun State from 2015 to 2023. Monthly gridded SST data from the National Oceanic and Atmospheric Administration (NOAA) Extended Reconstructed Sea Surface Temperature (ERSST) dataset were correlated with rainfall records from NiMet stations in Ijebu-Ode and Sagamu using Pearson correlation and lag correlation analyses. Results reveal a significant positive correlation (r = 0.61) between warm SST anomalies in the central Gulf of Guinea and above-normal rainfall in Ogun State, with a one-month lag period providing the strongest predictive signal. The relationship is strongest during the first rainy season months of April and May, consistent with established mechanisms of moisture advection from the ocean to the continent driven by the West African monsoon system. The study also notes a weakening of the SST-rainfall linkage during strong El Nino episodes, indicating modulation by remote Pacific Ocean forcing. Findings suggest that SST monitoring could serve as a practical predictor for seasonal rainfall outlooks in Ogun State. Keywords: sea surface temperature, rainfall, Gulf of Guinea, teleconnection, Ogun State.