Northeasterly monsoon winds and associated cloud cover currently anchor trader expectations for Taipei’s September 11 peak temperature near 29–30 °C. Central Weather Administration guidance and ensemble model runs indicate daytime maxima of 26–31 °C under persistent easterly flow that advects cooler, humid maritime air, with scattered showers further limiting insolation and surface heating. Recent CWA briefings note these seasonal winds will maintain elevated humidity and reduced diurnal range through the period, keeping probabilities tightly clustered between 28–30 °C while assigning lower odds to 31 °C or higher. Forecast updates on wind speed, shower timing, and boundary-layer moisture over the next 48 hours remain the key variables that could shift implied probabilities before resolution.