The approach of a Pacific frontal system is driving trader sentiment for Seattle’s September 2 minimum temperature, with National Weather Service guidance and ensemble models showing overnight lows centered in the mid-50s amid increasing cloud cover, southerly flow, and light-to-moderate rain. This setup favors modest radiative cooling suppression while marine air advection keeps readings close to the long-term September 2 average of 55°F. Spread across nearby bins (54–59°F) reflects minor differences in forecast timing of the front, boundary-layer mixing from gusty winds, and exact cloud onset, all of which can shift the daily low by a degree or two without altering the broader cool, moist regime.