Trader consensus on Polymarket prices a 34.5% implied probability for Beijing's highest temperature reaching exactly 19°C on April 4, closely trailed by 20°C at 22.5% and 18°C at 19.5%, reflecting tight uncertainty in one-day forecasts from ECMWF and GFS ensemble models clustering peaks at 17–20°C under partly cloudy, hazy skies. Recent stabilization of late-March highs around 20–22°C has given way to slightly cooler projections due to moderating southerly winds and potential northern cold air advection, with solar insolation reduced by aerosols—a common early spring feature in Beijing. Key variables include cloud cover evolution, wind shear, and boundary layer mixing, which could tip outcomes toward 21°C+ if clearer skies prevail or below 17°C on stronger northerlies. Updated model runs overnight and China Meteorological Administration observations will sharpen resolution as the market closes in.