**Recent forecasts for Chengdu on September 26, 2026, center on an overnight low near 21°C amid the early arrival of Huaxi Autumn Rain (华西秋雨), a seasonal pattern of persistent cloudy, rainy weather that reduces daytime heating and nighttime radiative cooling.** Multiple sources, including Chengdu Meteorological Observatory data and models like those referenced by Meteum and local weather services, project highs around 26°C and lows of 20–21°C, with 70–80% precipitation probability, high humidity (80%+), and light easterly or northeasterly winds. This setup narrows the diurnal temperature range through cloud cover and evaporative cooling from scattered rain, keeping minimums from dropping sharply. Historical late-September baselines for Chengdu show typical lows near 18–20°C, but the active rain system supports the current consensus slightly above that. Model agreement is reasonably tight, though small variations in rain timing or intensity could shift the exact low by 1–2°C. Trader sentiment, reflected in the closely matched 50% implied probabilities across the 17–27°C+ outcomes (with 22°C at 25%), captures this forecast clustering around 20–22°C while acknowledging residual uncertainty from evolving model runs and the dynamic autumn rain pattern. Key upcoming inputs include the next official forecast updates from Chinese meteorological agencies, which could refine the minimum temperature ahead of resolution.