Current National Weather Service and ensemble model guidance points to a San Francisco high in the mid-60s on August 30, driven by persistent strong onshore westerly flow and a deep marine layer that limits daytime heating. This setup favors the closely bunched 66–69°F outcomes that dominate trader positioning, with differentiation hinging on the precise depth of the marine layer, afternoon wind speeds near 15–20 mph, and any modest clearing that could allow a brief push toward 70°F. The forecast sits slightly below the 1991–2020 average high of roughly 70°F, reflecting typical late-summer coastal cooling from Pacific upwelling rather than any anomalous pattern. Updated model runs and NWS briefings through the weekend remain the key near-term catalysts for shifts in implied probabilities.