South San Francisco, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for South San Francisco, a city in San Mateo County, California.
Today
66°F
Light Rain
Rain. Mostly cloudy. High near 66, with temperatures falling to around 60 in the afternoon. South wind 6 to 15 mph, with gusts as high as 23 mph. Chance of precipitation is 80%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for South San Francisco
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 66°F | Light Rain | 6 to 15 mph S | 75% |
| Tonight | 52°F | Chance Light Rain then Mostly Cloudy | 7 mph E | 39% |
| Wednesday | 67°F | Sunny | 3 to 14 mph N | 3% |
| Wednesday Night | 53°F | Mostly Cloudy | 1 to 14 mph NW | 0% |
| Thursday | 70°F | Patchy Fog then Sunny | 1 to 8 mph NNW | 0% |
| Thursday Night | 53°F | Mostly Clear then Patchy Fog | 1 to 8 mph NNW | 0% |
| Friday | 71°F | Patchy Fog then Sunny | 1 to 7 mph N | 0% |
| Friday Night | 56°F | Mostly Clear | 1 to 7 mph N | 0% |
| Saturday | 70°F | Sunny | 2 to 7 mph NNE | 0% |
| Saturday Night | 57°F | Mostly Clear | 3 to 7 mph NW | 0% |
| Sunday | 69°F | Mostly Sunny | 2 to 8 mph NNW | 0% |
| Sunday Night | 57°F | Partly Cloudy | 2 to 8 mph WNW | 0% |
| Monday | 67°F | Partly Sunny | 2 to 10 mph NW | 1% |
| Monday Night | 57°F | Mostly Cloudy | 2 to 10 mph NW | 2% |
Forecast source: National Weather Service (api.weather.gov) for South San Francisco (37.655, -122.376). Updated through the day.
Growing snapshot for South San Francisco
Last spring frost
Dec 29
First fall frost
Dec 26
Growing season
365 days
Hardiness zone
10a
More local growing data for South San Francisco: nearby ZIP 94128 weather · frost dates · planting calendar · California frost dates
Nearby towns & communities
Atherton
Baywood Park
Belmont
Brisbane
Broadmoor
Burlingame
Colma
Daly City
El Granada
Emerald Lake Hills
Foster City
Half Moon Bay
Highlands
Hillsborough
La Honda
Ladera
Loma Mar
Millbrae
Montara
Moss Beach
North Fair Oaks
Pacifica
Pescadero
Portola Valley
Redwood City
San Bruno
San Carlos
San Mateo
West Menlo Park
Woodside
Climate data from the nearest NOAA station, San Francisco Intl Ap, Ca (1.1 mi from South San Francisco). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.