Recent National Weather Service and model guidance for San Francisco on August 22 points to a marine-dominated regime with onshore westerly flow and a persistent marine layer, keeping the daily maximum near 68–71°F and producing the tight market split between the 68–69°F and 70–71°F bins. Typical August climatology features strong Pacific sea-breeze cooling that caps interior warming, while subtle differences in low-level wind speed, cloud cover timing, and boundary-layer mixing determine whether readings reach the upper or lower end of that narrow range. Ensemble spread remains modest given the short lead time, but any late-day clearing or stronger gradient flow could nudge the peak a degree higher; forecasters will refine the official maximum through the evening using ASOS observations at KSFO.