**Forecast models and official guidance point to overnight lows near 28–29°C in Chongqing on August 23, 2026, as the dominant driver of current market-implied odds.** Subtropical high pressure, elevated humidity (typically 70%+), and the urban heat island effect limit nocturnal radiative cooling, keeping minimum temperatures elevated. Light winds and mostly clear to partly cloudy conditions further suppress temperature drops, consistent with climatological norms for late-August Chongqing where average lows hover around 25–27°C. Ensemble forecasts from sources such as the Met Office and AccuWeather show nighttime minima stabilizing in the 28°C range, with limited model spread supporting the heavy weighting toward 29°C (74.5%) and 28°C (19.5%). No significant synoptic shifts—such as incoming fronts or enhanced cloud cover—are indicated in the latest runs that would produce substantially cooler readings. Traders appear to be pricing in this consensus while assigning low probability to outliers below 26°C, reflecting both historical precedent and the absence of cooling mechanisms in current atmospheric conditions.