Disentangling the Regional and Contextual Dependencies of Climate Effects on Global Maize Yield

Maize is a cornerstone of global food security, yet the effects of interannual climate variability on its yield under varying production contexts remain not fully understood. Using Köppen climate zones, we coupled random forests with Shapley additive explanations to disentangle water‐heat drivers from three perspectives: yield state, cropping calendar, and their combined scenarios. Between 1982 and 2016, interannual climate variability explained 23%–45% of maize yield variability across zones and increasingly offset the yield benefits from technological advancements. From the yield state perspective, except in arid regions, the dominant climatic drivers differed between yield‐gain and yield‐loss scenarios. Notably, across all zones, key climatic drivers exhibited stronger strength in enhancing yield loss than in enhancing yield gain. From the cropping calendar perspective, compared to within‐year, cross‐year cropping in arid and warm temperate zones shifted dominant drivers from heat to water indices and triggered interactions among key drivers, amplifying yield risk under unfavorable conditions. Moreover, the contribution of extreme temperature indicators generally increased across all combined scenarios. In warm temperate zones, interannual variations in heat stress degree days became the dominant driver in cross‐year yield‐gain and yield‐loss scenarios, contributing 27% and 25%, respectively. Furthermore, two effect patterns were identified: one where main effects and interaction effects jointly amplified yield variability, and another where main effects were suppressed while interaction effects still amplified. Our findings enhance the comprehensive understanding of the climate–yield relationship and provide a scientific basis for developing targeted adaptation strategies.