Latest China Meteorological Administration and global ensemble forecasts from ECMWF and GFS indicate a highest temperature in Beijing on May 17 most likely between 20°C and 21°C, driven by a weak cold front delivering northerly winds, light rain, and widespread cloud cover that suppresses daytime solar heating. This setup explains the market's tight clustering around those outcomes, as earlier frontal passage and partial clearing could allow modest warming toward 22°C while prolonged overcast and boundary-layer mixing favor cooler readings near 19°C. Historical mid-May baselines near 26°C highlight how the current synoptic pattern deviates downward, with the next model runs and official CMA updates serving as the primary catalysts for any probability shifts before resolution.