Impact of Localized High Temperatures on Extreme Rainfall: Insights From the July 2023 Heavy Rainfall Event in the Beijing–Tianjin–Hebei Region Over the Taihang Mountains

Abstract Under global warming, extreme rainfall events have increased, causing annual economic losses of billions. Previous studies often treated high temperature and heavy rainfall as opposing phenomena, rarely considering their joint effects. However, emerging evidence suggests a direct link between antecedent heat conditions and subsequent precipitation extremes. As part of a typical extreme rainfall process, the high temperatures on July 26–27, 2023, drove the intensity and distribution of subsequent rainfall in the Beijing–Tianjin–Hebei region from July 29 to August 1. Numerical simulations and sensitivity experiments reveal that the July 26–27 heat event significantly intensified moisture transport and convective activity over the Taihang Mountains. Specifically, net moisture influx increased by 19.5% ± 24%, while convective intensity rose by 15% ± 13%. These heat‐induced enhancements collectively resulted in a 22.2% ± 7% increase in total rainfall. This mechanism provides a new explanation for future extreme rainfall events.