Fig. 7. (a), (b), (c) Spatial plot of mean summer hot day frequency (HDF) in the 2010s, 2040s, and 2090s. (d), (e) Spatial plot of the differences in the mean summer hot day frequency between the 2040s and 2010s and those between the 2090s and 2010s. All figures correspond to the SSP2-4.5 scenario.
In the 2010s, on average, heatwave events lasted no more than two weeks. In the 2040s, the largest HWD will increase to 15 days (Fig. 8 (b)). In the 2090s, several areas in Guangzhou and Foshan may experience heat waves lasting up to 22 days (Fig. 8 (c)). Despite the increase in the HDF, the HWD in several rural and coastal areas may decrease by 1–3 days in the 2040s. However, in the 2090s, fewer areas will experience a reduction in the HWD. Foshan is expected to have the most prolonged heatwaves, along with the largest increase in the HWD (5.5 and 13.9 days in the 2040s and 2090s, respectively). Despite a substantial increase in the number of individual very hot days (HDF) in coastal areas during the 2090s, our analysis shows that the greatest increase in consecutive very hot days (HWD) is expected to occur in Foshan and Jiangmen, due to their location farther from the coast and increasing urbanization.