Persistent rain and extensive cloud cover tied to a low-pressure system and Tropical Storm Saudel's outer circulation are the dominant factors capping daytime heating in Taipei on September 4. Official guidance and ensemble forecasts consistently show highs in the 26–29 °C range under mostly overcast skies and widespread showers, limiting solar insolation and surface warming. Light winds and high humidity further suppress temperature recovery between rain bands. Market-implied odds clustered around 30–31 °C reflect residual uncertainty in exact timing and intensity of any brief clearing, while lower probabilities for 32 °C or above acknowledge the strong model consensus for suppressed maxima. Updated Central Weather Administration and global model runs expected in the next 24–48 hours will refine these thresholds ahead of market resolution.