Recent forecast guidance from the China Meteorological Administration and ECMWF ensembles indicates persistent cloud cover and scattered showers across the Pearl River Delta on May 17, which will limit solar insolation and cap daytime heating near 27°C. High humidity levels above 80% and evaporative cooling from precipitation further moderate maximum temperatures, keeping the most probable outcome within the narrow 26–28°C band that dominates current trader pricing. This setup aligns with climatological patterns for mid-May, when the region transitions toward monsoon conditions that frequently suppress peaks below seasonal averages of 29–31°C. Model consensus on precipitation timing introduces the main uncertainty, as any earlier clearing could allow brief afternoon warming toward 28°C.