**Incoming cooler, moist air associated with northerly flow and widespread rain is the main driver shifting expectations toward lower overnight minima in Beijing on August 26.** Forecasts from multiple sources show a pronounced cooling trend after recent days with highs near 33–34°C: models converge on daytime highs of 24–27°C and overnight lows mostly between 18–23°C, with precipitation probabilities exceeding 60–90% that enhance radiational cooling under cloud cover while limiting daytime warming. This aligns with the market’s tight clustering of implied probabilities around 20–25°C outcomes (each 23–27%), as traders price in the consensus range rather than extremes. Historical climatology places the long-term average low near 20.4°C, providing context for why sub-18°C or above-26°C scenarios carry lower weight (11–20.5%) absent major forecast shifts. Key near-term variables include the exact timing and intensity of the rain-cooled air mass and any model divergence in boundary-layer moisture, with updated guidance expected within the next 24–48 hours before resolution.