Recent ensemble forecasts from the China Meteorological Administration and global models show a tight clustering of daily maximum temperatures around 29–31°C for Chengdu on August 20, driven by the Sichuan Basin’s characteristic subtropical monsoon conditions. High atmospheric moisture and residual soil wetness from prior showers are limiting surface heating, while variable cloud cover and weak steering flow allow scattered afternoon convection to either suppress or permit brief peaks near 31°C. Historical August climatology centers on 30–32°C highs, but short-term model spreads in boundary-layer humidity and insolation create the current market equilibrium near the median outcome. Updated CMA guidance expected within 24 hours will likely resolve the narrow spread.