Traders assign overwhelming implied probability to a 31°C high in Hong Kong on September 4, reflecting official Hong Kong Observatory measurements confirming that peak under partly cloudy conditions with light northwest winds. This outcome aligns with late-summer climatology for the region, where maximum temperatures frequently reach the low 30s Celsius absent strong monsoon or typhoon influence. Recent model consensus and real-time station data from the observatory reinforced the reading well before market close, leaving minimal room for alternative thresholds. A realistic challenge would require a post-event data revision or station-specific anomaly exceeding normal observational uncertainty, though such adjustments remain rare for established HKO records.