Latest National Weather Service guidance points to a San Francisco high near 68 °F today under persistent onshore flow and a strengthening marine layer that limits afternoon warming along the coast. Traders assigning roughly 70 % combined probability to the 70–73 °F bins appear to be weighting the chance of partial clearing or a slightly weaker sea breeze that could allow temperatures to edge a few degrees above the official forecast. The 68–69 °F outcome remains the next most likely at 13.5 % because the California Current and typical August stratus keep coastal maxima tightly clustered around climatological norms near 67–70 °F. Resolution hinges on the official maximum recorded at downtown or airport stations, where even modest shifts in cloud timing or wind speed can swing the final reading by 2–3 °F.