Wildfires can cause disastrous impacts on natural and human systems. Hydroclimatic extremes, such as droughts and high temperature anomalies, can affect the occurrence, intensity, and spread of wildfires. Moreover, these extremes may occur concurrently or consecutively, constituting compound extremes, and may cause even larger impacts on wildfire. While the influences of droughts and hot extremes on wildfires have been widely recognized, the relationship between wildfires and compound droughts and hot extremes is still unclear. In this study, we quantify the impact of concurrent/consecutive droughts and hot extremes (DHE) on wildfires within the fire season across the globe. Results show that the coincident rate (CR) of wildfires and concurrent/consecutive DHE is larger than that of individual droughts. Specifically, for the concurrent and consecutive DHE, the percentage of grids with CR higher than 0.5 is 36.17% and 35.89%, respectively, which is higher than that of individual droughts (32.96% and 30.19%). For different climate regions, the CR between concurrent/consecutive DHE and wildfires is relatively higher in humid regions. Moreover, hydroclimatic anomalies before wildfires are also evaluated, and results show that the wildfire in arid regions is closely related to antecedent wet conditions (and following hot extremes), while the wildfire in humid regions is more related to concurrent droughts and hot conditions. Findings of this study can be useful for wildfire prediction and management in a changing climate.
Ma et al. (2026) studied this question.