Numerical weather prediction models from agencies including China’s Meteorological Administration show a persistent subtropical high-pressure ridge over the Yangtze basin sustaining peak temperatures near 37–38°C in Chongqing on August 17. Low-level wind speeds and elevated humidity limit evaporative cooling, while the city’s basin topography and urban heat island amplify daytime maxima above the long-term August average of roughly 34°C. Minor model differences in the timing and extent of convective cloud cover or moisture influx create the narrow spread between the leading 37°C and 38°C outcomes. Updated runs incorporating latest satellite and surface observations will refine resolution criteria tied to official station readings.