Recent model consensus and the onset of Chongqing’s Huaxi autumn rain period around September 15 have driven trader focus toward maximum temperatures of 24–27 °C on the 20th. Persistent cloud cover, light-to-moderate rain, and reduced solar insolation from the interaction of southerly moisture with northerly cold air are limiting daytime heating below the historical late-September average near 28–29 °C. Current forecasts from multiple sources cluster highs in the mid-20s Celsius, with modest spread reflecting uncertainty in exact rainfall timing and local topography effects. The market’s closely matched leading outcomes reflect this narrow scientific range, while lower-probability extremes would require either rapid clearing or stronger cold-air advection. Updated China Meteorological Administration guidance and next model runs will provide the clearest near-term signals.