Hong Kong Observatory and global models indicate the minimum temperature on August 19 will most likely fall between 26–28 °C, keeping those three outcomes tightly bunched in the market. Typical August nocturnal conditions—high humidity, light southerly flow, and limited radiative cooling under partly cloudy skies—produce this narrow range, while any increase in cloud cover or light rain would suppress the low toward 26 °C and clearer, calmer conditions would allow 28 °C. Ensemble spreads remain modest at this lead time, reflecting normal model uncertainty in boundary-layer moisture and urban heat retention rather than a major weather shift. Updated HKO guidance and overnight observations tomorrow morning will resolve the final value.