Beijing's late-August climate features typical highs near 31°C driven by subtropical high pressure and strong solar insolation, yet the tightly bunched market probabilities around 31–35°C reflect uncertainty in short-range model guidance for August 23. Ensemble forecasts show modest spread arising from variable cloud cover and scattered thunderstorm potential, which can suppress afternoon maxima by 2–4°C through evaporative cooling and reduced insolation. High humidity and the urban heat-island effect add further variability, while climatological baselines indicate only a small chance of extremes above 36°C or below 30°C this late in the season. Updated National Meteorological Center runs and boundary-layer observations over the next 48 hours will likely narrow the range.