Traders see 24–25°C as the near-even frontrunners for Chengdu’s September 13 maximum because ensemble forecasts from major models show only marginal daytime warming under persistent cloud cover and light rain. The Sichuan Basin’s high humidity and surrounding terrain limit solar insolation while enhancing evaporative cooling, keeping temperatures near or slightly below the late-summer climatological mean of roughly 26°C. Recent surface observations indicate overcast skies and scattered showers have already suppressed heating on the 12th, with similar synoptic conditions expected to persist into the 13th. Minor model differences in timing and coverage of precipitation create the tight 30%–30.5% split, as even small shifts in cloud thickness or wind could tip the daily peak by 1°C. Official station readings, which resolve at 0.1°C increments, will determine the outcome once data are finalized.