San Francisco weather, explained by a local pattern
San Francisco is a city of microclimates: the Mission can bask at 70°F while Karl the Fog smothers Ocean Beach at 55°F. Summer is often colder than fall — September and October are the true warm season. Rain is a winter-only phenomenon; the year-round question isn't precipitation but which neighborhood the fog owns that hour.
How to use this page
The verdict above reads the next 12 hours of official National Weather Service hourly data for central San Francisco and reduces it to one answer. The bar chart underneath shows the precipitation probability hour by hour — taller and bluer means wetter. A quick reading guide: probabilities under 25% are generally safe to plan through, 40% and above during your specific window deserves a plan B, and any active NWS alert (which appears automatically above the chart) outranks everything else on this page.
Conditions can differ across the metro, so for your exact neighborhood — and to check a specific date and time instead of right now — use the ZIP code checker, which also finds your longest dry window of the day. For a deeper read on what these percentages actually mean, see our guide: What does a 40% chance of rain actually mean?