<p>With the global warming, growing concern has been attracted on changes in surface air temperature (SAT), not only focusing on daily mean (T2m) and maximum (T2x), but also on hot extremes (T2m and T2x larger than the critical values at 95th percentile thresholds, T2m95 and T2 × 95). The impacts on T2m/T2x and T2m95/T2 × 95 over the Beijing-Tianjin-Hebei region of China (BTH), as well as the Beijing, Tianjin and Hebei subregions were explored, using numerical experiments with the nested WRF model under the bias-corrected global SSP245 scenario data for the years between 2005–2014 and 2026–2035. The results revealed that T2m/T2x generally increased, especially over the plain areas, showing changes in the average only, rather than changes in the variability. Changes in T2x were smaller than those for T2m over the BTH region and Beijing subregion, whereas the probability for T2 × 95 were comparable to those for T2m95, especially over the plain areas. T2m/T2x changes over urban areas were larger than those over the nonurban areas. The occurrence probabilities of hot extremes generally increased, which were larger over the Bohai gulf and the southeastern BTH region (T2m95/T2 × 95), the eastern (T2m95 only) and northeastern (T2 × 95 only) Beijing subregion and the whole Tianjin subregion (T2m95/T2 × 95) for both the enhanced intensity and enlarged number of extreme days, while smaller over the central-southern BTH region (T2m95/T2 × 95) and the southeastern Beijing subregion (T2 × 95 only) for the enhanced intensity but decreased number of extreme days. Changes in the frequency and the intensity for both shorter and longer durations of T2m and T2x hot extremes were noteworthy between EX10 and EX11 over the BTH region and the subregions. Therefore, the impacts due to climate change expressed marked subregional characteristics over the BTH region, within which changes in the average and hot extremes were more significant over the Beijing and Tianjin subregion, especially for the Tianjin subregion.</p>