Traders have converged on a 31°C or higher outcome for Hong Kong’s maximum temperature on May 22 because official observations from the Hong Kong Observatory recorded a peak at or above that threshold. This aligns with the seasonal outlook for normal to above-normal temperatures across May–July, driven by long-term warming trends and supportive atmospheric conditions. Typical May climatology in the region features daytime highs near 28–30°C, with recent model guidance and real-time measurements confirming conditions that pushed readings into the low 30s. While forecast uncertainty exists in short-term model runs, the post-event data release leaves little room for downward revision, though any future reanalysis of station readings could theoretically adjust the final verified value.