Official forecasts from the Shanghai Meteorological Bureau and supporting model runs, including GFS data, converge on a daily maximum of 22°C for October 3 under persistent overcast skies, light to moderate rain, and northeasterly winds that suppress daytime warming. High humidity near 90% and cloud cover limit the diurnal range, keeping temperatures aligned with seasonal autumn baselines rather than allowing brief spikes. This strong model consensus and real-time observational trends underpin the market's near-certain 22°C outcome. A sudden break in cloud cover or revised station readings could theoretically shift the recorded high, though current atmospheric conditions make such deviations improbable before final verification.