Latest numerical weather prediction models from sources including the China Meteorological Administration and global ensembles indicate a September 29 high temperature in Beijing centered in the mid-20s °C, driven by a transitional synoptic pattern with northwest winds, clearing skies after recent moisture, and seasonal autumn cooling. Diurnal ranges and urban heat island effects introduce small uncertainties that differentiate the closely matched 26–28 °C market-implied outcomes, while any model spread in cloud cover or timing of maximum heating could shift the peak by 1–2 °C. Official 36–48 hour updates from the Beijing Meteorological Bureau will provide the clearest resolution signals ahead of the daily maximum.