Traders price the San Francisco high for August 8 most heavily in the 70–73 °F range because National Weather Service guidance and ensemble models show a typical late-summer marine layer keeping onshore flow moderate and limiting daytime warming. Recent model runs place the peak near 72 °F, consistent with August climatology of roughly 69–72 °F and the absence of strong offshore winds or subsidence that would allow greater heating. Small differences among the leading bins hinge on the precise strength and timing of the marine inversion and any brief clearing that could add a degree or two; a deeper or more persistent stratus deck would favor the 70–71 °F outcome, while modest model spread around wind speed keeps 74–75 °F in play at lower probability. No major heat-wave signals or forecast shifts have altered the outlook in the past 48 hours.