Traders converged on 27°C as Hong Kong’s lowest temperature on August 25 because official observations from the Hong Kong Observatory recorded nighttime minimums holding precisely at this threshold under typical late-summer subtropical conditions. High humidity, light winds, and the absence of any strong cold fronts or typhoon-induced cooling kept surface temperatures from dropping further, consistent with historical August baselines where daily lows average 26–28°C. Model runs and station data showed no significant deviations overnight. Revised measurements from additional monitoring sites or post-event quality checks remain the only realistic factors that could alter the outcome, though current verified records indicate strong consensus around this exact value.