Large increase in extreme fire weather synchronicity over Europe

Abstract Synchronous extreme fire weather can significantly increase the probability of fire ignition and spread, posing compounding threats to fire management efforts and potentially overwhelming firefighting capabilities. While substantial evidence indicates that weather conditions conducive to wildfires will likely become more frequent with higher levels of global warming, changes in extreme fire weather synchronicity remain understudied. Here, we quantify the synchronicity of extreme fire weather in Europe by analysing historical data of the Canadian fire weather index (FWI) from 1981 to 2022 and projecting FWI future scenarios with temperature increases from 1 °C to 6 °C and precipitation changes from −40% to +60%. Our results highlight Central Europe (CEU) as a significant hotspot, with synchronicity increases of up to 389%, while the Mediterranean region could see increases up to 66%. These findings emphasize the growing need for enhanced cross-border coordination and proactive fire management strategies to address the rising likelihood of concurrent extreme fire weather conditions in a warming climate.