Persistent tropical moisture and widespread cloud cover from ongoing monsoon patterns are capping daytime heating in Taipei, keeping forecast highs clustered around 29–32°C for September 5. Recent model runs show variable rainfall timing and intensity—stronger or earlier showers would favor the 31°C outcome by limiting insolation, while clearer intervals could allow brief warming toward 32–33°C. Northwest winds and high dew points near 25°C further moderate peaks, consistent with September climatology where afternoon convection often prevents extremes. Traders appear to weigh these near-term uncertainties evenly across the top three bins, with resolution hinging on the final Central Weather Administration analysis.