Figure (IMAGE) Science China Press Caption The spatial patterns of mean numbers ((a)–(c)) and decadal trends ((d)–(f)), and time series ((g)–(i)) of the three types of extreme hot days within compound heatwaves: independent hot day (the left column), independent hot night (the middle column), and concurrent daytime-nighttime hot extreme (the right column) over China in 1961−2017. Symbol ‘+’ in ((d)–(f)) indicates that the trend of a 5°×5° grid has passed the two tailed Student’s t test at the 95% confidence level. Texts in ((g)–(i)) are the trends with the corresponding statistical significance listed in parentheses. Credit ©Science China Press Usage Restrictions Use with credit. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.