Marine layer and persistent onshore flow from the Pacific are anchoring San Francisco’s August 5 high near the low-to-mid 70s, with National Weather Service and AccuWeather guidance converging on 70–73 °F under partly sunny skies and a moderate sea breeze. These conditions match the market’s leading 72–73 °F (45.5 %) and 74–75 °F (26.5 %) bins, reflecting both climatological norms—daily August maxima average ~70 °F—and the current absence of strong offshore warming. A broader regional heat wave has raised inland temperatures but is buffered locally by the marine inversion, keeping extreme bins (>78 °F) below 3 % combined. Updated model runs overnight show little change in the thermal profile through the afternoon peak, supporting the current trader consensus until evening observations confirm the daily maximum.