Spatial and temporal variability of climate extremes and their impact on maize yield in North-Central Nigeria.

Climate change is threatening global food security by instigating hot and dry spells of varying intensity and frequency, driven by the increased atmospheric concentration of greenhouse gasses. Agriculture is the main economic driver in North-Central Nigeria; however, the influence and contribution of climate extremes in inducing maize yield variations are not well reported. In this study, 26 agriculturally related extreme climate indices were derived using a 39-year (1982 − 2020) daily temperature and rainfall data collected from 25 weather stations. Stepwise regression was used to identify the nine most influential climate extreme indices that elucidate the variations in rainfed maize yield. Across all weather stations, a gradual drying was observed, supported by statistically significant (p < 0.05) declining trends in most rainfall-related extreme indices, particularly consecutive wet days and heavy rainfall days. Most temperature-related extreme indices showed notably higher and statistically significant warming rates (p < 0.05), except for the cold spell duration indicator and cold nights. Warm nights, featuring significantly increasing rates of 0.12–1.1 days per decade, were the most influential factor contributing to a reduction in maize yield by 19.6 kg/ha per unit increase. Additionally, maize yield increased at a rate of 32.5 kg/ha per unit increase in the daily diurnal temperature. The selected climatic extremes from the stepwise regression analysis demonstrated a good predictive capacity for rainfed maize yield variations. The study showed that North-Central Nigeria is particularly susceptible to severe droughts and heat waves that can seriously deteriorate sustainable maize production in the future. [ABSTRACT FROM AUTHOR]