Forecast models from agencies including the China Meteorological Administration indicate Guangzhou’s July 19 maximum will likely fall between 32–34 °C under the influence of the western Pacific subtropical high, which maintains warm, humid southerly flow from the South China Sea. Scattered afternoon thunderstorms, driven by moderate instability and southwesterly flow, introduce the main uncertainty: early or widespread convection can enhance cloud cover and evaporative cooling to cap readings near 32–33 °C, while delayed or localized activity may allow brief clearing and peaks of 34–35 °C. Climatological July highs average near 33 °C, with urban heat-island effects adding modest elevation on clear days. Market-implied odds reflect this narrow spread and the sensitivity of the daily maximum to precise timing of precipitation within the 24-hour window.