Recent forecasts for Shanghai on October 10 show overnight lows clustered between 17–20°C under partly cloudy to clear skies and light northerly winds, supporting the market’s emphasis on 19°C and 20°C as leading outcomes. Stable high-pressure conditions following mild daytime highs of 24–26°C on October 9 limit strong advection, while modest radiative cooling overnight—typical for early autumn—keeps minimums from dropping below 17°C or exceeding 21°C in most model runs. Consensus from GFS and regional guidance indicates minimal day-to-day variability, with any slight downward revision in dew points or increased clearing potentially favoring the 18–19°C band. Traders are weighting the tight distribution of official guidance and limited forecast spread ahead of final observations.