Traders see the lowest temperature in San Francisco on August 28, 2026, clustering around 52–59°F because National Weather Service forecasts and current observations place the overnight minimum in the mid- to upper-50s amid a strengthening marine layer and onshore flow. Typical late-August climatology shows average lows near 56°F, with the Pacific-driven cooling moderated by variable low clouds and dew points in the mid-50s. Recent model runs highlight slight uncertainty in the exact minimum depending on the timing of any fog clearance or wind shifts, keeping the top four bins nearly tied. Official resolution will use verified observations from downtown or airport stations, with no major deviations from seasonal norms expected.