Recent forecasts for Chengdu indicate daytime highs near 30–31°C through mid-June, aligning with the market’s tight clustering around those outcomes. Primary drivers include the onset of the East Asian monsoon, which brings elevated humidity, frequent cloud cover, and scattered thunderstorms that limit solar heating and promote evaporative cooling. Local basin topography traps moisture while variable steering winds and shortwave troughs determine whether convection develops before or after peak heating. Model consensus shows modest spread in cloud timing and rainfall amounts on June 18, creating the narrow probability distribution between 29°C and 32°C; clearer skies or delayed storms would favor the upper end, while earlier or heavier precipitation would cap temperatures closer to 29°C. Updated runs from the China Meteorological Administration and global ensembles over the next 24–48 hours will likely sharpen this range.