Frost dates for 94128 — San Francisco, 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 Francisco compares
- In a typical year, frost nights in San Francisco 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 San Jose, CA, 56 km away, the last frost here is 4 days 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 Francisco, 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, 2 km away (elevation 7 ft (2 m)).
ZIP codes in San Francisco: 94102 94103 94104 94105 94107 94108 94109 94110 94111 94112 94114 94115 94116 94117 94118 94119 94120 94121 94122 94123 94124 94125 94126 94127 94128 94129 94130 94131 94132 94133 94134 94137 94139 94140 94141 94142 94143 94144 94145 94146 94147 94151 94158 94159 94160 94161 94163 94164 94172 94177 94188
Frost dates near San Francisco
- Millbrae Dec 29 · Dec 26
- San Bruno Jan 11 · Jan 10
- South San Francisco Dec 29 · Dec 26
- Burlingame Dec 29 · Dec 26
- Brisbane Dec 29 · Dec 26
- Pacifica Jan 11 · Jan 10
- Daly City Dec 30 · Dec 25
- San Mateo Dec 29 · Dec 26
Frequently asked questions
When is the last frost in San Francisco, CA?
The median last spring frost in San Francisco, 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 Francisco, 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 Francisco, CA?
About 362 days between the median last spring frost and first fall frost.
What planting zone is San Francisco, CA?
San Francisco, CA is in USDA hardiness zone 10a.