**Northeast monsoon flow continues to moderate daytime heating across northern Taiwan ahead of September 18, with official Central Weather Administration guidance and ensemble models showing highs most likely between 27–30 °C under partly to mostly cloudy skies and light northeasterly winds.** Persistent cloud cover and scattered showers limit insolation while the maritime air mass keeps surface temperatures below the seasonal 30–32 °C climatological peak; minor model differences in boundary-layer moisture and wind strength account for the tight clustering of market probabilities across the 27–33 °C range. Updated high-resolution runs and the next CWA briefing will refine whether any break in cloud cover allows a brief push toward 31–32 °C or whether additional showers keep readings capped near 28 °C.