When is the last frost in Inverness, CA?

For ZIP code 94937, the average last spring frost (32°F) is January 29, based on NOAA 1991-2020 climate normals for the Occidental, CA weather station. There is a 1-in-10 chance of a frost after March 17.

When is the first frost in Inverness, CA?

The average first fall frost (32°F) is December 30. There is a 1-in-10 chance of frost by December 1, so tender plants are at risk from that point on.

How long is the growing season in 94937?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 347 days long.

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 94937Inverness, CA

The average last spring frost in Inverness is January 29 and the average first fall frost is December 30, giving a typical growing season of about 347 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jan 29
Average first fall frost: Dec 30
Growing season: 347 days

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)	Feb 3 · Mar 24 · Apr 24	Nov 20 · Dec 8 · Jan 9	258 days	100%
Frost / freeze (32°F)	Dec 17 · Jan 29 · Mar 17	Dec 1 · Dec 30 · Feb 27	347 days	67%
Hard freeze (28°F)	—	—	365 days	10%

Where these dates come from

ZIP code 94937 is matched to the NOAA station Occidental, CA, 31.1 km away, at 865 ft elevation (370 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Occidental, CA (used)	865 ft	Jan 29	Dec 30
Bodega 6 Wsw, CA	63 ft	Jan 1	Dec 31
Petaluma Ap, CA	20 ft	Feb 28	Nov 25
San Rafael Civic Ctr, CA	120 ft	Jan 11	Dec 21

Frost dates near Inverness

Marshall, CA 94940 · last Mar 20, first Nov 13
Point Reyes Station, CA 94956 · last Feb 28, first Nov 25
Olema, CA 94950 · last Jan 16, first Dec 18
Tomales, CA 94971 · last Mar 20, first Nov 13
Dillon Beach, CA 94929 · last Mar 20, first Nov 13
Nicasio, CA 94946 · last Jan 11, first Dec 21
Lagunitas, CA 94938 · last Jan 16, first Dec 18
Forest Knolls, CA 94933 · last Jan 16, first Dec 18

Frequently asked questions

When is the last frost in Inverness, CA?: For ZIP code 94937, the average last spring frost (32°F) is January 29, based on NOAA 1991-2020 climate normals for the Occidental, CA weather station. There is a 1-in-10 chance of a frost after March 17.
When is the first frost in Inverness, CA?: The average first fall frost (32°F) is December 30. There is a 1-in-10 chance of frost by December 1, so tender plants are at risk from that point on.
How long is the growing season in 94937?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 347 days long.
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.