TRENDS IN WEATHER FLUCTUATION AT ILE-IFE, A TROPICAL RAINFOREST LOCATION IN SOUTHWESTERN NIGERIA, 2011 – 2022

Abstract

Weather in the tropical rainforest agro-ecologies is highly variable, and as such, it calls for an accurate and timely observation of the defining meteorological parameters.  Intensified weather variability observed in the recent years (2011-2022) at Obafemi Awolowo University (OAU) campus, Ile-Ife, Nigeria (7.5^oN, 4.5^oE) and the attendant climate change scenarios are well manifest. The objective of this study was to provide up-to-date information on fluctuations in weather variables and the influence of climate change at the location. Minimum and maximum air temperature, relative humidity, rainfall amount, solar radiation, soil moisture, soil temperature, and soil heat flux were monitored from installed automatic weather stations (AWS). Hourly meteorological data thus obtained were subjected to descriptive and inferential statistical analyses; bar charts, mean, standard deviation, standard error of the mean, range, and variation index. Regression analysis was also carried out on the datasets.  The mean annual rainfall obtained for the 12-year study was 1505 mm with a range of 675 – 2829 mm and a b-value of - 45.62 mm with a significant R² value of 0.48. The period minimum, mean, and maximum values of the air temperature were 22–25 °C, 25.2–28.2^oC and 32–33^oC respectively, for the location. The air temperature was shown to have a positive correlation with the solar radiation. Increase in weather variability is being attributed to frequent high rainfall amounts recorded within a few months (June – August) rather than reduced total annual rainfall or increased temperature. An increase in weather variability is attributed to climate change.