**Incoming heavy rainfall and associated cooling are the dominant drivers of trader positioning on Chongqing’s August 29 low temperature.** Official and model guidance from the past 24–48 hours highlight a strong precipitation event tied to easterly flow and northern cold-air influence, expected to deliver widespread rain (locally heavy to torrential) across central and western districts from the night of August 28 into August 29 daytime. This will increase cloud cover, reduce daytime heating, and enhance evaporative and radiative cooling overnight. Forecasts from multiple sources converge on a daytime high of roughly 26–32 °C (lower than the recent 36–39 °C readings), with overnight lows most commonly placed between 21–24 °C. Heavier rain bands and stronger winds could push minima toward or below 21 °C in some locales, while lighter or delayed rainfall would favor readings near 24 °C. The near-even market-implied odds between the 24 °C, 21 °C, and sub-19 °C buckets reflect model spread on exact rainfall timing, intensity, and the depth of cold-air advection. Resolution hinges on the final 24-hour minimum recorded at official stations; updated model runs and Chongqing Meteorological Bureau briefings over the next 24 hours will likely tighten the distribution. Historical late-August baselines (typical lows ~25–26 °C) underscore how anomalous the current setup is.