Recent monsoon-driven thunderstorms and persistent cloud cover across the Pearl River Delta are keeping overnight radiative cooling limited in Guangzhou, with forecast models showing minimum temperatures clustered around 26–28°C for August 28. High humidity (near 90%) and scattered showers or thunderstorms overnight suppress temperature drops, while daytime heating remains strong under partly cloudy skies. Historical climatology places the average low near 25°C, but current conditions and model spread—particularly in precipitation timing—create genuine uncertainty across the 25–28°C range. China Meteorological Administration updates and final 24-hour observational data will refine the exact minimum before market resolution.