Recent National Weather Service and NOAA model guidance for Seattle shows the overnight low on September 26 centered in the upper 40s, with ensemble means near 48–49°F under partly cloudy skies and light northerly flow. This aligns with climatological norms for late September, when radiational cooling under weakening marine influence typically produces minimums of 47–52°F. Key variables include the strength of the surface high and any marine push from Puget Sound, which could add or subtract several degrees. Traders appear to weight the consensus forecast heavily while assigning residual probability to warmer outcomes from increased cloud cover or cooler runs from stronger offshore flow. Updated model cycles and local observations tomorrow morning will drive final resolution.