FrostDateByZip

Frost dates for 94920Belvedere Tiburon, CA

The average last spring frost in Belvedere Tiburon is January 16 and the average first fall frost is December 18, giving a typical growing season of about 334 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost
Jan 16

Safer after Feb 25 (1-in-10 risk)

Average first fall frost
Dec 18

Possible by Nov 30 (1-in-10 risk)

Growing season
334 days

First frost typically in 49 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.
TemperatureLast spring: 90% / 50% / 10% chanceFirst fall: 10% / 50% / 90% chanceGrowing season (50%)Years with at least one
Light frost (36°F)Jan 29 · Mar 5 · Apr 5Nov 12 · Nov 29 · Dec 21265 days100%
Frost / freeze (32°F)Dec 21 · Jan 16 · Feb 25Nov 30 · Dec 18 · Jan 19334 days86%
Hard freeze (28°F)Dec 9 · Dec 30 · Jan 23Dec 4 · Dec 24 · Jan 21365 days27%

Where these dates come from

ZIP code 94920 is matched to the NOAA station Kentfield, CA, 10.7 km away, at 145 ft elevation (3 ft lower than the ZIP code's center). Nearby stations for comparison:

StationElevationAvg last frostAvg first frost
Kentfield, CA (used)145 ftJan 16Dec 18
Richmond, CA20 ftJan 4Jan 2
San Francisco Dwtn, CA150 ft——
San Rafael Civic Ctr, CA120 ftJan 11Dec 21

Frost dates near Belvedere Tiburon

Frequently asked questions

When is the last frost in Belvedere Tiburon, CA?
For ZIP code 94920, the average last spring frost (32°F) is January 16, based on NOAA 1991-2020 climate normals for the Kentfield, CA weather station. There is a 1-in-10 chance of a frost after February 25.
When is the first frost in Belvedere Tiburon, CA?
The average first fall frost (32°F) is December 18. There is a 1-in-10 chance of frost by November 30, so tender plants are at risk from that point on.
How long is the growing season in 94920?
In half of years, the frost-free season (between the last and first 32°F frost) is at least 334 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.