**Official HKO forecasts point to a highest temperature of 29–30°C on August 31, 2026, aligning closely with the market’s leading outcomes (30°C at 28.5%, 29°C at 25%).** A broad trough of low pressure over the South China Sea and Guangdong coast is driving unsettled conditions, with mainly cloudy skies, occasional showers, and squally thunderstorms expected. These reduce solar insolation and promote evaporative cooling, capping daytime maxima below the late-August climatological average of ~31°C. Model consensus and HKO guidance show a daytime range of 26–30°C, with high humidity (75–95%) and rain probabilities of 70–80% further limiting heat buildup. A transition toward drier northerly flow begins around September 1, but it arrives too late to meaningfully raise August 31 temperatures. The tight clustering of probabilities around 29–30°C reflects this narrow, rain-suppressed outcome window, while lower odds for 32°C+ or sub-28°C capture residual model spread and any unexpected clearing.