Recent National Weather Service model guidance and ensemble runs indicate a persistent marine layer and moderate onshore flow will cap daytime warming in San Francisco, keeping the August 12 high most likely between 68–71°F. This coastal pattern, typical for mid-August, features fog and stratus that delay heating until afternoon, when temperatures often peak near the long-term average of 70°F. Subtle differences in the strength of the sea breeze and 925 mb temperatures create the narrow spread between the leading market bins, with any inland warming or weaker marine push potentially pushing readings into the low 70s. Updated NWS briefings and next model cycles tomorrow morning will provide the final observational constraints before resolution.