Recent National Weather Service and model guidance indicate a typical late-summer marine layer will limit San Francisco's August 6 high to the low-to-mid 70s, with sea breezes and coastal stratus suppressing further warming. This aligns with the market's concentration on 72-73°F as the modal outcome, reflecting historical August averages near 69°F plus modest recent warmth from a weakening inland high-pressure ridge. Traders weigh ensemble forecasts showing limited daytime heating against the small risk of clearer skies allowing a brief push into the mid-70s, while probabilities taper sharply above 77°F due to the persistent Pacific influence that has kept recent daily maxima in the upper 60s to low 70s. Updated model runs tomorrow morning will refine these implied odds.