The overwhelming market consensus on 31°C as Beijing’s daily high stems from real-time surface observations and official meteorological data aligning precisely with that threshold. National weather services and numerical models, including those incorporating local station readings and urban heat-island effects, have shown afternoon temperatures peaking at this level amid typical late-September conditions of moderate humidity and light winds. With the observation window closing, traders have priced in final verification from authoritative sources with near-certainty. Only an unexpected post-processing revision, instrument calibration adjustment, or rare data-quality flag from monitoring agencies could alter the outcome, scenarios that historical records show occur infrequently for major urban stations.