Persistent overcast skies and widespread rainfall from a slow-moving frontal system have capped daytime heating in Zhengzhou, producing forecast maximums of 24–25 °C according to consensus model runs and official guidance. This aligns with current surface observations showing suppressed sensible heat flux under high humidity and reduced solar insolation, consistent with late-summer climatology when monsoon influences often moderate extremes. The 99.5 % market-implied probability on 25 °C reflects traders’ assessment of these locked-in conditions, with resolution likely based on official station data. Only an abrupt late-day clearing or localized measurement anomaly could realistically shift the outcome, though both remain low-probability given ongoing precipitation.