Trader consensus centers on 30–31°C for Guangzhou’s August 3 high because the latest model guidance from global ensembles and the China Meteorological Administration shows persistent cloud cover and scattered moderate rain suppressing daytime heating. Recent observations indicate a moist monsoon flow and possible weak frontal passage that has already trimmed highs to the 29–32°C range over the past several days, well below the long-term August climatological average near 33°C. Differentiating the closely matched leading outcomes hinges on forecast uncertainty in rainfall timing and intensity: heavier or earlier showers favor 30°C or lower, while partial clearing could allow brief peaks near 31–32°C. Updated CMA and ECMWF runs expected within the next 24 hours will likely refine these probabilities ahead of market resolution.