FrostDateByZip

Frost dates for 92022El Cajon, CA

The average last spring frost in El Cajon is January 6 and the average first fall frost is December 21, giving a typical growing season of about 350 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost
Jan 6

Safer after Feb 7 (1-in-10 risk)

Average first fall frost
Dec 21

Possible by Dec 1 (1-in-10 risk)

Growing season
350 days

First frost typically in 54 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 6 · Feb 6 · Mar 3Nov 18 · Dec 6 · Dec 29300 days99%
Frost / freeze (32°F)Dec 13 · Jan 6 · Feb 7Dec 1 · Dec 21 · Jan 15350 days73%
Hard freeze (28°F)Dec 8 · Dec 31 · Jan 15Dec 7 · Dec 30 · Jan 14365 days16%

Where these dates come from

ZIP code 92022 is matched to the NOAA station El Cajon, CA, 3.3 km away, at 495 ft elevation (59 ft higher than the ZIP code's center). Nearby stations for comparison:

StationElevationAvg last frostAvg first frost
El Cajon, CA (used)495 ftJan 6Dec 21
San Diego Montgomery Fld, CA417 ft——
El Capitan Dam, CA600 ftMar 19Dec 8
San Diego Miramar Nas, CA477 ft——

Frost dates near El Cajon

Frequently asked questions

When is the last frost in El Cajon, CA?
For ZIP code 92022, the average last spring frost (32°F) is January 6, based on NOAA 1991-2020 climate normals for the El Cajon, CA weather station. There is a 1-in-10 chance of a frost after February 7.
When is the first frost in El Cajon, CA?
The average first fall frost (32°F) is December 21. 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 92022?
In half of years, the frost-free season (between the last and first 32°F frost) is at least 350 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.