Official observations from the Hong Kong Observatory establish an absolute daily minimum of 27°C on September 12, 2026, aligning with late-summer climatology under elevated pressure, elevated humidity, and limited nocturnal radiative cooling. This measurement, drawn from the agency's standardized station data and consistent with nearby model guidance showing overnight lows near 27–28°C, underpins the market's overwhelming consensus. Traders assign negligible probability to deviations because finalized records rarely undergo material revision, though an unanticipated data correction or station anomaly remains a low-likelihood scenario that could theoretically shift resolution.