Latest forecasts from the Hong Kong Observatory point to overnight minima in the mid-20s Celsius for May 21 under a stable subtropical high-pressure ridge that limits radiative cooling and favors southerly maritime air. This setup aligns with mid-May climatological norms, where daily lows typically range 23–26°C amid pre-monsoon moisture and variable cloud cover. Numerical weather prediction models show limited spread, with any increase in clear skies or lighter winds potentially pushing the minimum toward 26–28°C, while stronger onshore flow could hold it near 24–25°C. Traders appear to weigh these near-term model consensus outputs heavily, as resolution depends on the official King’s Park station reading rather than broader seasonal trends. Updated Observatory guidance and fresh model runs over the next 48 hours will likely tighten the probability distribution ahead of the date.