Recent northeasterly monsoon winds have increased moisture and cloud cover over northern Taiwan, moderating daytime heating in Taipei ahead of September 15. Official forecasts from the Central Weather Administration and global models indicate a highest temperature most likely between 28–31°C, with scattered showers expected to limit solar insolation and prevent stronger warming. This aligns with market-implied odds clustering around 29–31°C, where small differences in precipitation timing, wind speed, or cloud persistence can shift the daily maximum by 1–2°C. Historical September baselines near 31°C provide context, yet the current pattern favors slightly cooler outcomes than peak summer conditions. Updated model runs and local observations over the next 48 hours will refine these thresholds.