Urban‐Rural Gradient in Urban Heat Island Variations Responsive to Large‐scale Human Activity Changes during Chinese New Year Holiday

Large-scale human activity changes in megacities during Chinese New Year (CNY) are believed to significantly affect urban heat islands (UHIs). However, the urban-rural gradient in UHI variations responsive to human activity changes in cities remains largely unclear. Using in-situ surface air temperature obtained from a meteorological network that includes 3000-plus stations, we show that the mean UHI intensity (UHII) in 31 Chinese capitals is 0.52 +/- 0.23 K during the CNY holiday and 0.77 +/- 0.29 K in the reference period, indicating a UHII reduction of 0.25 +/- 0.20 K during the holiday. The reduced UHII decreased more from city core (0.54 K) to city periphery (0.071 K). We find that these UHII reductions were larger at night than during the day and were larger in northern subtropical and warm temperate climates than in other climates. These UHII reductions were mainly attributable to the decline in anthropogenic heat release.