Millbrae, CA frost dates
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 Millbrae compares
- In a typical year, frost nights in Millbrae 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.
- Millbrae shares its weather station with South San Francisco, CA, 6 km away, so the two have the same frost dates.
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
Millbrae, 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, 4 km away (elevation 7 ft (2 m)).
Frost dates near Millbrae
- San Bruno Jan 11 · Jan 10
- Burlingame Dec 29 · Dec 26
- South San Francisco Dec 29 · Dec 26
- Pacifica Jan 11 · Jan 10
- Brisbane Dec 29 · Dec 26
- San Mateo Dec 29 · Dec 26
- Montara Jan 11 · Jan 10
- Daly City Dec 30 · Dec 25
- El Granada Feb 6 · Dec 17
- Moss Beach Jan 11 · Jan 10
Frequently asked questions
When is the last frost in Millbrae, CA?
The median last spring frost in Millbrae, 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 Millbrae, 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 Millbrae, CA?
About 362 days between the median last spring frost and first fall frost.
What planting zone is Millbrae, CA?
Millbrae, CA is in USDA hardiness zone 10a.