**Current forecasts from the National Weather Service and private models indicate an overnight low near 55–58°F for San Francisco on October 1, consistent with the early-October climatological average of about 55.5°F.** A strong high-pressure ridge over the western U.S. is driving above-normal daytime warmth and suppressing the marine layer, resulting in clear to partly cloudy skies and light winds that limit radiative cooling. This setup supports the market-implied balance between the 47°F-or-below and 66°F-or-higher buckets, as traders weigh the potential for slight forecast shifts from model updates or localized microclimate effects at official reporting stations. Key resolution thresholds hinge on the precise minimum recorded at the primary San Francisco observation site, with new model runs and evening observations likely to refine the outlook before the date.