Current National Weather Service and model guidance point to a highest temperature of 70–73°F for San Francisco on August 7, driven by a persistent marine layer and onshore flow that limits daytime warming along the immediate coast. Typical August climatology features an average high near 69–70°F, with sea-surface temperatures and coastal upwelling suppressing heat buildup; recent ensemble runs show only modest deviations from this baseline absent a stronger offshore ridge. Traders have priced the 70–71°F and 72–73°F bins highest because forecast uncertainty remains centered on the strength of the sea breeze and any late-day clearing, while probabilities drop sharply above 75°F given historical rarity and the current lack of extreme-heat signals in NOAA guidance. Updated model runs tomorrow will refine these odds ahead of market resolution.