**Recent forecasts from multiple models point to overnight lows in Taipei on September 8 clustering around 22–23 °C, aligning with the closely matched leading market outcomes (22 °C at 34.5 % and 23 °C at 32.5 %).** The primary driver is the approaching first autumn northeast monsoon, which will begin influencing northern Taiwan around September 9 but already shapes conditions on the 8th through strengthening northeasterly flow and reduced moisture after a passing low-pressure system or distant typhoon influence clears. This setup favors moderate radiative cooling under partly cloudy to clearer skies, with dew points near 22 °C limiting how far temperatures drop. Historical September baselines for Taipei show typical overnight lows near 24–26 °C, so the modest 1–3 °C cooling reflects the early, relatively weak monsoon surge rather than a strong cold-air outbreak. Key differentiating variables include exact cloud cover (thicker clouds trap heat and raise minima), wind speeds (stronger northeasterlies enhance mixing and cooling), and any last-minute model shifts in the monsoon timing. Official Central Weather Administration updates and refined ensemble runs in the next 48 hours will likely tighten the range, with traders weighing these against the current consensus favoring 21–23 °C.