**Persistent cloud cover and widespread rainfall are moderating overnight temperatures in Chongqing, keeping the minimum near 20–21 °C on September 22.** Multiple forecast sources, including regional models and international guidance, show highs of 21–24 °C and lows of 20–21 °C under mostly cloudy, rainy conditions with light winds. This pattern aligns with the market-implied 21 °C outcome at 50 % while explaining the near-equal weighting on 16 °C or below (46 %). Traders appear to weigh the possibility that stronger or more prolonged rain could enhance evaporative cooling or that local terrain effects in Chongqing’s hilly setting could produce a slightly lower reading than the broader consensus. September climatology places average lows near 22 °C, but the current wet regime—driven by ongoing monsoon influences and a series of rain episodes—has already produced similar or slightly cooler minima in recent days. Resolution hinges on the precise timing and intensity of precipitation overnight, which official updates from the China Meteorological Administration and refined model runs will clarify. The tight spread between the top two outcomes reflects genuine uncertainty around these short-term variables rather than any major divergence in long-range guidance.