This dataset is the data of summer days in China, with a spatial resolution of 0.25 °, and the time is from 1948 to 2016. The data format is csv and tif. This dataset is generated based on the Princeton Global Forcings global 0.25 ° climate dataset published by Princeton University and the extreme climate indicators published by WMO. This dataset covers the main land areas in China (including Hong Kong, Macao and Taiwan), excluding islands and reefs in the South China Sea. The csv data can be opened by using excel and other software. The first column is the latitude value, the second column is the longitude value, and the third column is the index calculation value of each year. The Tif data is WGS84 coordinates. Each index file includes 69 bands, corresponding to the years 1948 to 2016. It can be opened with ENVI and other software.