Forecast consensus from National Weather Service and ensemble models points to a San Francisco overnight low in the mid-50s Fahrenheit for September 26, aligning with the closely matched 54–57°F market bands that together exceed 85% implied probability. Marine-layer stratus and moderate onshore flow from the Pacific limit radiative cooling overnight, while light winds and partly cloudy skies prevent significant departures from the 55.6°F climatological average. Model spreads arise mainly from subtle variations in boundary-layer moisture and wind direction, which can shift the minimum by 1–2°F. No major synoptic changes are expected before resolution, keeping trader focus on the final NWS observation.