Datasets of Heatwave Hazard Indices of China under 1.5°C and 2°C Global Warming

According to the national standard (GB/T29457-2012), the Heatwave Index (HI) serves as the metric for characterizing the severity of heatwaves. Based on the magnitude of the HI, heatwaves are categorized into three levels: mild heatwave (2.8 ≤ HI < 6.5), moderate heatwave (6.5 ≤ HI < 10.5), and severe heatwave (HI ≥ 10.5), indicating the intensity and impact of different heatwave events. A heatwave event is defined as a weather process lasting 10 consecutive days or longer during which the HI reaches a specified threshold. The probability of heatwave occurrence is calculated by averaging the annual frequency of heatwave events, with the comprehensive hazard index reflecting the severity of heatwaves.