When is the last frost in El Mirage, AZ?

For ZIP code 85335, the average last spring frost (32°F) is January 20, based on NOAA 1991-2020 climate normals for the Youngtown, AZ weather station. There is a 1-in-10 chance of a frost after February 18.

When is the first frost in El Mirage, AZ?

The average first fall frost (32°F) is December 15. There is a 1-in-10 chance of frost by November 28, so tender plants are at risk from that point on.

How long is the growing season in 85335?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 331 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 85335El Mirage, AZ

The average last spring frost in El Mirage is January 20 and the average first fall frost is December 15, giving a typical growing season of about 331 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jan 20
Average first fall frost: Dec 15
Growing season: 331 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 14 · Mar 4	Nov 17 · Dec 2 · Dec 18	291 days	100%
Frost / freeze (32°F)	Dec 23 · Jan 20 · Feb 18	Nov 28 · Dec 15 · Jan 7	331 days	95%
Hard freeze (28°F)	Dec 13 · Jan 3 · Feb 1	Dec 10 · Dec 29 · Jan 22	365 days	49%

Where these dates come from

ZIP code 85335 is matched to the NOAA station Youngtown, AZ, 2.6 km away, at 1,135 ft elevation (0 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Youngtown, AZ (used)	1,135 ft	Jan 20	Dec 15
Litchfield Park, AZ	1,040 ft	Jan 7	Dec 24
Phoenix Deer Valley Muni Ap, AZ	1,455 ft	Jan 8	Dec 25
Wittmann 1Se, AZ	1,683 ft	Feb 5	Dec 11

Frost dates near El Mirage

Surprise, AZ 85374 · last Jan 20, first Dec 15
Youngtown, AZ 85363 · last Jan 20, first Dec 15
Sun City, AZ 85351 · last Jan 20, first Dec 15
Sun City West, AZ 85376 · last Jan 20, first Dec 15
Glendale, AZ 85307 · last Jan 7, first Dec 24
Peoria, AZ 85380 · last Jan 20, first Dec 15
Waddell, AZ 85355 · last Jan 20, first Dec 15
Litchfield Park, AZ 85340 · last Jan 7, first Dec 24

Frequently asked questions

When is the last frost in El Mirage, AZ?: For ZIP code 85335, the average last spring frost (32°F) is January 20, based on NOAA 1991-2020 climate normals for the Youngtown, AZ weather station. There is a 1-in-10 chance of a frost after February 18.
When is the first frost in El Mirage, AZ?: The average first fall frost (32°F) is December 15. There is a 1-in-10 chance of frost by November 28, so tender plants are at risk from that point on.
How long is the growing season in 85335?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 331 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.