Heavy rainfall and associated cloud cover from an active rainstorm over Guangdong province are the dominant factors capping daytime heating in Guangzhou today, with official forecasts from regional meteorological agencies projecting a maximum near 30°C. High humidity and suppressed solar insolation under overcast skies differentiate the closely matched 30–32°C outcomes, as even modest breaks in cloud could allow brief warming toward the upper end of that range. Subtropical monsoon conditions typical of early August normally support higher peaks, but persistent precipitation and the associated atmospheric instability are shifting trader consensus toward these moderate values, with new model guidance or real-time observations likely to refine resolution probabilities before the daily maximum is recorded.