Recent National Weather Service guidance and model consensus indicate a shallow marine layer and lingering upper-level ridging will support San Francisco highs in the mid-70s on August 2, keeping the city cooler than inland heat-wave areas while slightly above seasonal norms. The key variables differentiating the closely bunched 74–79 °F market bins are the precise depth and timing of the marine inversion, strength of the afternoon sea breeze, and any late-day clearing of coastal stratus. A deeper layer or stronger onshore flow would favor the lower-probability 72–73 °F outcome, whereas reduced marine influence or warmer offshore flow could push readings toward 78–81 °F. Updated NHC and local model runs over the next 24 hours will refine these thresholds ahead of market resolution.