San Francisco High Near 70°F Expected on Sept. 28
The National Weather Service forecasts a high temperature near 70°F (21°C) in San Francisco on September 28, 2026. The day is expected to start with a marine layer that will clear by the morning, followed by light southwest winds. Coastal moderation from the Pacific Ocean and the timing of fog dissipation are key factors influencing the temperature. The forecast aligns with late-September climatology, which typically features stable high pressure and moderate onshore westerlies. The temperature is expected to hover around the seasonal average of 71°F (21.7°C), with minimal risk of precipitation.
