When is the last frost in San Quentin, CA?

Frost occurs in about 22% of years at the nearest NOAA station (Richmond, CA), so there is no reliable average last frost date.

When is the first frost in San Quentin, CA?

Frost occurs in about 22% 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.

Frost dates for 94974San Quentin, CA

Frost occurs in about 22% of years near San Quentin, based on NOAA 1991-2020 records for the Richmond, CA station.

Frost occurs in about 22% 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.

Spring dates: chance of a frost AFTER the date. Fall dates: chance of a frost BEFORE the date.
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 22 · Jan 17 · Feb 23	Dec 2 · Dec 24 · Jan 21	343 days	80%
Frost / freeze (32°F)	Dec 14 · Jan 4 · Jan 26	Dec 11 · Jan 2 · Jan 22	365 days	22%
Hard freeze (28°F)	—	—	365 days	0%

Where these dates come from

ZIP code 94974 is matched to the NOAA station Richmond, CA, 9.8 km away, at 20 ft elevation (13 ft lower than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Richmond, CA (used)	20 ft	Jan 4	Jan 2
Kentfield, CA	145 ft	Jan 16	Dec 18
San Rafael Civic Ctr, CA	120 ft	Jan 11	Dec 21
San Francisco Dwtn, CA	150 ft	—	—

Frost dates near San Quentin

San Quentin, CA 94964 · last Jan 16, first Dec 18
Corte Madera, CA 94925 · last Jan 16, first Dec 18
San Rafael, CA 94901 · last Jan 11, first Dec 21
Larkspur, CA 94977 · last Jan 16, first Dec 18
Greenbrae, CA 94904 · last Jan 16, first Dec 18
Kentfield, CA 94914 · last Jan 16, first Dec 18
Mill Valley, CA 94942 · last Jan 16, first Dec 18
Ross, CA 94957 · last Jan 16, first Dec 18

Frequently asked questions

When is the last frost in San Quentin, CA?: Frost occurs in about 22% of years at the nearest NOAA station (Richmond, CA), so there is no reliable average last frost date.
When is the first frost in San Quentin, CA?: Frost occurs in about 22% 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.