When is the last frost in Concord, CA?

For ZIP code 94529, the average last spring frost (32°F) is January 7, based on NOAA 1991-2020 climate normals for the Concord Wwtp, CA weather station. There is a 1-in-10 chance of a frost after February 1.

When is the first frost in Concord, CA?

The average first fall frost (32°F) is December 19. 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 94529?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 346 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 94529Concord, CA

The average last spring frost in Concord is January 7 and the average first fall frost is December 19, giving a typical growing season of about 346 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jan 7
Average first fall frost: Dec 19
Growing season: 346 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)	Jan 6 · Feb 9 · Mar 6	Nov 15 · Dec 2 · Dec 24	297 days	99%
Frost / freeze (32°F)	Dec 19 · Jan 7 · Feb 1	Dec 1 · Dec 19 · Jan 12	346 days	80%
Hard freeze (28°F)	Dec 14 · Dec 31 · Jan 20	Dec 10 · Dec 29 · Jan 14	365 days	25%

Where these dates come from

ZIP code 94529 is matched to the NOAA station Concord Wwtp, CA, 3.4 km away, at 40 ft elevation (35 ft lower than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Concord Wwtp, CA (used)	40 ft	Jan 7	Dec 19
Concord Buchanan Fld, CA	18 ft	Jan 9	Dec 14
Martinez Wtp, CA	40 ft	Feb 28	Nov 22
Mt Diablo Junction, CA	2,170 ft	Mar 8	Dec 22

Frost dates near Concord

Concord, CA 94522 · last Jan 7, first Dec 19
Pleasant Hill, CA 94523 · last Jan 7, first Dec 19
Walnut Creek, CA 94598 · last Jan 7, first Dec 19
Martinez, CA 94553 · last Feb 28, first Nov 22
Pittsburg, CA 94565 · last Jan 9, first Dec 14
Lafayette, CA 94549 · last Jan 3, first Jan 1
Clayton, CA 94517 · last Feb 15, first Dec 2
Alamo, CA 94507 · last Jan 3, first Jan 1

Frequently asked questions

When is the last frost in Concord, CA?: For ZIP code 94529, the average last spring frost (32°F) is January 7, based on NOAA 1991-2020 climate normals for the Concord Wwtp, CA weather station. There is a 1-in-10 chance of a frost after February 1.
When is the first frost in Concord, CA?: The average first fall frost (32°F) is December 19. 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 94529?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 346 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.