California · NWS MTR office

South San Francisco, CA weather

It is 54°F and clear at San Francisco, San Francisco International Airport as of Oct 28, 2:05 AM PDT. Overnight: Mostly Clear, low near 51°F. Forecast from the National Weather Service, issued Oct 28, 1:26 AM PDT.

Updated Oct 28, 2:19 AM PDT (snapshot)

Current conditions

Temperature

54°F

Clear

Wind

—

Humidity 88% · dew point 50°F

Pressure · visibility

30.01 inHg

Visibility 10 mi

Observed at San Francisco, San Francisco International Airport (KSFO), Oct 28, 2:05 AM PDT. Station readings can lag or be missing.

Alerts for this area

No active NWS alerts cover the South San Francisco forecast zone right now.

Around the NWS MTR forecast area

2 active alerts cover zones served by the MTR office near South San Francisco:

  • Coastal Flood Advisory (2)

From the alert snapshot of Oct 28, 2026, 5:12 AM EDT. California has 8 active alerts: see them all.

For official warnings, check weather.gov and your local authorities. OpenForecast repeats National Weather Service alerts and may be delayed or incomplete. Follow instructions from emergency officials.

Next 24 hours

Hourly forecast for South San Francisco (local time)
TimeTempForecastPrecip. chanceWind
Wed 4 AM51°FPartly Cloudy0%NNE 2 mph
Wed 5 AM51°FPatchy Fog0%NNE 2 mph
Wed 6 AM51°FPatchy Fog0%NNE 2 mph
Wed 7 AM51°FPatchy Fog0%N 2 mph
Wed 8 AM51°FPatchy Fog0%N 2 mph
Wed 9 AM55°FSunny0%NNE 2 mph
Wed 10 AM58°FSunny0%NE 2 mph
Wed 11 AM60°FSunny0%NE 2 mph
Wed 12 PM63°FSunny0%NE 2 mph
Wed 1 PM65°FSunny0%N 3 mph
Wed 2 PM67°FMostly Sunny0%WNW 5 mph
Wed 3 PM67°FSunny0%W 7 mph
Wed 4 PM66°FSunny0%W 8 mph
Wed 5 PM65°FSunny0%W 8 mph
Wed 6 PM62°FMostly Clear0%W 8 mph
Wed 7 PM59°FMostly Clear0%W 8 mph
Wed 8 PM58°FPartly Cloudy0%W 2 mph
Wed 9 PM57°FPartly Cloudy0%W 2 mph
Wed 10 PM56°FPartly Cloudy0%W 2 mph
Wed 11 PM55°FMostly Cloudy0%SW 1 mph
Thu 12 AM55°FMostly Cloudy0%SW 1 mph
Thu 1 AM54°FMostly Cloudy0%SW 1 mph
Thu 2 AM54°FMostly Cloudy0%SE 1 mph
Thu 3 AM53°FMostly Cloudy0%SE 1 mph

Hourly values come from the NWS gridded forecast for the 2.5 km grid square that covers the city's center point. Conditions elsewhere in South San Francisco can differ.

7-day forecast

Overnight

Low 51°F

Mostly clear, with a low around 51. North northeast wind around 2 mph.

Wednesday

High 68°F·Low 52°F

Patchy fog before 8am. Mostly sunny. High near 68, with temperatures falling to around 65 in the afternoon. North northeast wind 2 to 10 mph.

Wednesday Night: Mostly cloudy, with a low around 52. South southwest wind 1 to 9 mph.

Thursday

High 67°F·Low 53°F

Partly sunny, with a high near 67. East wind 1 to 7 mph.

Thursday Night: Mostly cloudy, with a low around 53. West southwest wind 2 to 7 mph.

Friday

High 65°F·Low 51°F

Sunny, with a high near 65.

Friday Night: Partly cloudy, with a low around 51.

Saturday

High 62°F·Low 53°F

Partly sunny, with a high near 62.

Saturday Night: A slight chance of rain between 11pm and 4am. Partly cloudy, with a low around 53.

Sunday

High 63°F·Low 54°F

Sunny, with a high near 63.

Sunday Night: Mostly clear, with a low around 54.

Monday

High 66°F·Low 56°F

Mostly sunny, with a high near 66.

Monday Night: Mostly cloudy, with a low around 56.

Tuesday

High 66°F

A chance of rain after 10am. Partly sunny, with a high near 66.

Nearby cities

Larger cities in the area

Other cities in San Mateo County

See every city we cover in California, or check all active alerts.

About this forecast

Forecast office
South San Francisco is served by the National Weather Service MTR forecast office, forecast zone PZZ531.
Location used
The Census Bureau's internal point for South San Francisco (37.6551, -122.3762), in San Mateo County. Population: 64,660 (2024 estimate), number 138 of the 296 California cities on this site.
Radar
Nearest NWS radar: KMUX. View it on radar.weather.gov.

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Sources

  • Forecast, hourly forecast, observations and alerts: National Weather Service API, api.weather.gov/points/37.6551,-122.3762 (forecast issued Oct 28, 1:26 AM PDT).
  • Official forecast page: forecast.weather.gov.
  • City location and population: U.S. Census Bureau, Vintage 2024 population estimates and 2024 Gazetteer files.
  • Snapshot taken Oct 28, 2026. The NWS and Census Bureau do not endorse OpenForecast.

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