Traders see the highest probabilities clustered in the 70-73°F range for San Francisco’s peak temperature on August 22, driven by persistent marine-layer influence and onshore flow typical of late summer. National Weather Service guidance and ensemble models indicate modest warming under a stable high-pressure ridge, tempered by cool Pacific air and possible morning fog that delays surface heating. Minor differences among leading bins hinge on the timing of any afternoon clearing and exact wind speeds, which control how much solar radiation reaches the urban core. Historical August averages near 70°F and low model spread reinforce the tight distribution, with new forecast updates expected to sharpen resolution criteria around the daily maximum.