**Trader consensus at 100% on 25°C reflects real-time observational data and forecast model agreement showing Shanghai's daily maximum temperature reaching precisely that threshold on October 1.** Multiple sources, including Met Office guidance and regional models, indicate a daytime peak near 25°C under mostly cloudy conditions with light northeasterly winds, consistent with early October climatology where highs average around 22–24°C. Minor probabilities attached to 21°C or 26°C capture residual uncertainty in station-specific readings or brief model spreads, yet the tight clustering around 25°C underscores converging evidence from surface observations and numerical weather prediction. A realistic challenge would require an unexpected late-day warming spike or revision in official China Meteorological Administration data exceeding typical error margins for the Shanghai station network.