Short-term forecast model runs from the Hong Kong Observatory and global ensembles currently indicate minimum temperatures on August 17 most likely falling between 26–28 °C, producing closely matched market-implied probabilities across those bins. Day-to-day variability stems from the strength and timing of the prevailing southwest monsoon flow, the degree of cloud cover and nocturnal radiative cooling, and any weak easterly wave or tropical disturbance that could enhance or suppress mixing of cooler marine air. Historical August climatology places typical overnight lows near 26–27 °C, so traders are weighting the latest ensemble spread and any revisions to boundary-layer moisture and wind forecasts ahead of the final observational reading used for market resolution.