Official Hong Kong Observatory measurements established a daily maximum of 31°C on September 15, 2026, under easterly flow with moderate humidity near 70% and partly cloudy skies that limited further solar heating. This outcome aligns with climatological September averages near 31°C and real-time station data showing peaks in the low 30s before any convective cooling. Trader consensus at 100% for 31°C reflects confidence in finalized HKO absolute daily max values, which incorporate verified observational records rather than forecasts. Minor probabilities for adjacent outcomes account for rare post-processing revisions or instrument calibration checks, though such adjustments are uncommon once preliminary hourly data are confirmed.