When is the last frost in Red Rock, AZ?

For ZIP code 85145, the average last spring frost (32°F) is February 6, based on NOAA 1991-2020 climate normals for the Picacho 8 Se, AZ weather station. There is a 1-in-10 chance of a frost after March 5.

When is the first frost in Red Rock, AZ?

The average first fall frost (32°F) is December 9. There is a 1-in-10 chance of frost by November 22, so tender plants are at risk from that point on.

How long is the growing season in 85145?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 308 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 85145Red Rock, AZ

The average last spring frost in Red Rock is February 6 and the average first fall frost is December 9, giving a typical growing season of about 308 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Feb 6
Average first fall frost: Dec 9
Growing season: 308 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)	Feb 2 · Feb 28 · Mar 26	Nov 11 · Nov 29 · Dec 15	271 days	100%
Frost / freeze (32°F)	Jan 6 · Feb 6 · Mar 5	Nov 22 · Dec 9 · Dec 26	308 days	99%
Hard freeze (28°F)	Dec 17 · Jan 14 · Feb 13	Dec 1 · Dec 19 · Jan 22	342 days	83%

Where these dates come from

ZIP code 85145 is matched to the NOAA station Picacho 8 Se, AZ, 9.3 km away, at 1,981 ft elevation (144 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Picacho 8 Se, AZ (used)	1,981 ft	Feb 6	Dec 9
Eloy 4 Ne, AZ	1,545 ft	Feb 24	Nov 28
Arizona City, AZ	1,525 ft	Feb 28	Nov 21
Robson Rch, AZ	1,495 ft	Feb 7	Dec 3

Frost dates near Red Rock

Picacho, AZ 85141 · last Feb 6, first Dec 9
Marana, AZ 85653 · last Feb 6, first Dec 9
Rillito, AZ 85654 · last Feb 11, first Dec 2
Cortaro, AZ 85652 · last Feb 11, first Dec 2
Eloy, AZ 85131 · last Feb 24, first Nov 28
Tucson, AZ 85743 · last Feb 11, first Dec 2
Arizona City, AZ 85123 · last Feb 28, first Nov 21
Catalina, AZ 85738 · last Apr 2, first Nov 11

Frequently asked questions

When is the last frost in Red Rock, AZ?: For ZIP code 85145, the average last spring frost (32°F) is February 6, based on NOAA 1991-2020 climate normals for the Picacho 8 Se, AZ weather station. There is a 1-in-10 chance of a frost after March 5.
When is the first frost in Red Rock, AZ?: The average first fall frost (32°F) is December 9. There is a 1-in-10 chance of frost by November 22, so tender plants are at risk from that point on.
How long is the growing season in 85145?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 308 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.