Recent National Weather Service guidance and ensemble model consensus indicate a high near 62°F for San Francisco on August 31 under mostly cloudy skies and persistent southwest winds of 10–20 mph. This setup reflects the dominant marine layer and strong onshore flow from the cool California Current, which limits afternoon heating and keeps coastal maxima several degrees below the late-August climatological average of roughly 70°F. Trader emphasis on the 66–67°F and 64–65°F bins, despite official projections, stems from uncertainty over the degree of afternoon clearing or temporary marine-layer thinning that could add a couple of degrees; stronger stratus or sustained flow would instead favor the lower end of that range. The next updated model runs and NWS forecast discussions will provide the clearest signals ahead of resolution.