Frost dates for 94402 — San Mateo, CA
Frost is light and occasional here — typically a few cold nights around midwinter (about 0 a year). Cover tender plants when frost is forecast.
How San Mateo compares
- In a typical year, frost nights in San Mateo fall between December 26 and December 29. In 1 year in 10 the first frost comes as early as December 11, or the last frost as late as January 13.
- Compared with Daly City, CA, 20 km away, the last frost here is 1 day earlier than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 11 |
| 50% (median) | December 29 |
| 10% (safe for tender plants) | January 13 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | December 11 |
| 50% (median) | December 26 |
| 90% (late) | January 13 |
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 Mateo, 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 San Francisco Intl Ap, CA weather station, 8 km away (elevation 7 ft (2 m)).
ZIP codes in San Mateo: 94401 94402 94403 94404 94497
Frost dates near San Mateo
- Burlingame Dec 29 · Dec 26
- Belmont Jan 17 · Dec 12
- San Carlos Jan 17 · Dec 12
- Millbrae Dec 29 · Dec 26
- Redwood City Jan 17 · Dec 12
- San Bruno Jan 11 · Jan 10
- Half Moon Bay Feb 6 · Dec 17
- El Granada Feb 6 · Dec 17
Frequently asked questions
When is the last frost in San Mateo, CA?
The median last spring frost in San Mateo, CA is December 29. There is still about a 10% chance of frost after January 13, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in San Mateo, CA?
The median first fall frost is December 26, with about a 10% chance of frost before December 11.
How long is the growing season in San Mateo, CA?
About 362 days between the median last spring frost and first fall frost.
What planting zone is San Mateo, CA?
San Mateo, CA is in USDA hardiness zone 10a.