San Carlos, CA frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 6 a year). Cover tender plants when frost is forecast.
How San Carlos compares
- In a typical year, frost nights in San Carlos fall between December 12 and January 17. In 1 year in 10 the first frost comes as early as November 24, or the last frost as late as February 16.
- San Carlos shares its weather station with Redwood City, CA, 4 km away, so the two have the same frost dates.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 20 |
| 50% (median) | January 17 |
| 10% (safe for tender plants) | February 16 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 24 |
| 50% (median) | December 12 |
| 90% (late) | January 14 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Gardening where frost is rare
San Carlos, CA only freezes on a few winter nights, so the usual "plant after the last frost" rule doesn't apply. Heat and rainfall decide the seasons instead:
- Cool-season crops (lettuce, broccoli, peas, carrots) grow best from fall through late winter.
- Warm-season crops (tomatoes, peppers, beans, squash) do best planted in late winter to spring, and again in late summer for a fall crop — midsummer heat can stop tomatoes setting fruit.
- Heat lovers (okra, sweet potatoes, melons) can be planted through spring and early summer.
About these dates
Based on 1991–2020 NOAA climate normals for the Redwood City, CA weather station, 3 km away (elevation 30 ft (9 m)).
Frost dates near San Carlos
- Belmont Jan 17 · Dec 12
- Redwood City Jan 17 · Dec 12
- San Mateo Dec 29 · Dec 26
- Atherton Jan 17 · Dec 12
- Menlo Park Feb 25 · Nov 25
- Palo Alto Feb 1 · Dec 7
- Stanford Feb 1 · Dec 7
- Burlingame Dec 29 · Dec 26
- Portola Valley Mar 21 · Dec 15
- Half Moon Bay Feb 6 · Dec 17
Frequently asked questions
When is the last frost in San Carlos, CA?
The median last spring frost in San Carlos, CA is January 17. There is still about a 10% chance of frost after February 16, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in San Carlos, CA?
The median first fall frost is December 12, with about a 10% chance of frost before November 24.
How long is the growing season in San Carlos, CA?
About 329 days between the median last spring frost and first fall frost.
What planting zone is San Carlos, CA?
San Carlos, CA is in USDA hardiness zone 10a.