资源环境科技发展态势分析平台

World-wide urbanization has resulted in more hot extremes in urban areas than surrounding rural areas. Most studies focused on the contribution of urbanization to daytime hot extremes (DayHot), while the contribution to compound hot extremes (CoHot) that considers the concurrence of both daytime and nighttime heat is less understood. Here we quantify the urbanization contributions across the world by comparing the characteristics of hot extremes between urban and rural areas from 3401 meteorological stations classified by 30m-resolution impervious area data. We find more significant increases in frequency, duration and intensity of CoHot over most urban stations, where urbanization contributes to 12.5%, 15.4% and 16.7% of the increases respectively. Urbanization also contributes to the increase in frequency of DayHot, but has weaker impacts on the duration and intensity of Dayhot. This study implies that urbanization effects on the characteristics of hot extremes might be underestimated if only considers DayHot.