When is the last frost in Brea, CA?

For ZIP code 92823, the average last spring frost (32°F) is January 17, based on NOAA 1991-2020 climate normals for the Chino Ap, CA weather station. There is a 1-in-10 chance of a frost after February 22.

When is the first frost in Brea, CA?

The average first fall frost (32°F) is December 19. There is a 1-in-10 chance of frost by November 27, so tender plants are at risk from that point on.

How long is the growing season in 92823?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 335 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 92823Brea, CA

The average last spring frost in Brea is January 17 and the average first fall frost is December 19, giving a typical growing season of about 335 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jan 17
Average first fall frost: Dec 19
Growing season: 335 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 21 · Feb 24 · Mar 29	Nov 12 · Dec 1 · Dec 18	278 days	100%
Frost / freeze (32°F)	Dec 18 · Jan 17 · Feb 22	Nov 27 · Dec 19 · Jan 17	335 days	85%
Hard freeze (28°F)	Dec 11 · Jan 3 · Jan 28	Dec 7 · Dec 30 · Jan 23	365 days	29%

Where these dates come from

ZIP code 92823 is matched to the NOAA station Chino Ap, CA, 16 km away, at 650 ft elevation (183 ft lower than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Chino Ap, CA (used)	650 ft	Jan 17	Dec 19
Anaheim, CA	235 ft	—	—
Fullerton Muni Ap, CA	96 ft	—	—
Pomona/Fairplex, CA	999 ft	Jan 8	Dec 28

Frost dates near Brea

Yorba Linda, CA 92886 · last Jan 17, first Dec 19
Atwood, CA 92811 · last —, first —
Placentia, CA 92871 · last —, first —
Anaheim, CA 92807 · last —, first —
Brea, CA 92821 · last —, first —
Chino Hills, CA 91709 · last Jan 17, first Dec 19
Diamond Bar, CA 91765 · last Jan 8, first Dec 28
Fullerton, CA 92831 · last —, first —

Frequently asked questions

When is the last frost in Brea, CA?: For ZIP code 92823, the average last spring frost (32°F) is January 17, based on NOAA 1991-2020 climate normals for the Chino Ap, CA weather station. There is a 1-in-10 chance of a frost after February 22.
When is the first frost in Brea, CA?: The average first fall frost (32°F) is December 19. There is a 1-in-10 chance of frost by November 27, so tender plants are at risk from that point on.
How long is the growing season in 92823?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 335 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.