Recent National Weather Service guidance and ensemble model runs point to a highest temperature in the upper 60s to low 70s for San Francisco on August 22, with a marine layer and persistent westerly flow limiting daytime heating. Onshore advection of cooler Pacific air, reinforced by coastal upwelling, keeps the city cooler than inland areas, while variable cloud cover and the precise depth of the marine layer introduce the main uncertainty in peak readings. Typical August climatology shows a normal high near 69 °F, placing the market’s leading 70-71 °F bin near the expected outcome, yet modest differences in afternoon clearing or wind strength can easily shift the daily maximum by a few degrees across the closely bunched probability distribution. Updated short-range model output and morning observations will refine the final range before resolution.