Frost dates for 94131San Francisco, CA
Frost occurs in about 20% of years near San Francisco, based on NOAA 1991-2020 records for the Pacifica 4 Sse, CA station.
Frost occurs in about 20% of years. Frost-tender plants can usually grow year-round, but cover them if a rare cold snap is forecast.
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Dec 24 · Jan 25 · Mar 11 | Dec 1 · Jan 4 · Feb 19 | 350 days | 67% |
| Frost / freeze (32°F) | Dec 23 · Jan 11 · Feb 12 | Dec 22 · Jan 10 · Feb 5 | 365 days | 20% |
| Hard freeze (28°F) | — | — | 365 days | 5% |
Where these dates come from
ZIP code 94131 is matched to the NOAA station Pacifica 4 Sse, CA, 17.3 km away, at 475 ft elevation (63 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Pacifica 4 Sse, CA (used) | 475 ft | Jan 11 | Jan 10 |
| San Francisco Dwtn, CA | 150 ft | — | — |
| San Francisco Oceanside, CA | 8 ft | Dec 30 | Dec 25 |
| San Francisco Intl Ap, CA | 8 ft | Dec 29 | Dec 26 |
Frost dates near San Francisco
- San Francisco, CA 94114 · last —, first —
- Daly City, CA 94016 · last Jan 11, first Jan 10
- Brisbane, CA 94005 · last —, first —
- South San Francisco, CA 94080 · last Dec 29, first Dec 26
- Sausalito, CA 94966 · last Jan 4, first Jan 2
- San Bruno, CA 94066 · last Dec 29, first Dec 26
- Oakland, CA 94615 · last —, first —
- Pacifica, CA 94044 · last Dec 29, first Dec 26
Frequently asked questions
- When is the last frost in San Francisco, CA?
- Frost occurs in about 20% of years at the nearest NOAA station (Pacifica 4 Sse, CA), so there is no reliable average last frost date.
- When is the first frost in San Francisco, CA?
- Frost occurs in about 20% of years at the nearest NOAA station.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.