When is the last frost in Tucson, AZ?

For ZIP code 85751, the average last spring frost (32°F) is February 5, based on NOAA 1991-2020 climate normals for the Tucson Intl Ap, AZ weather station. There is a 1-in-10 chance of a frost after March 2.

When is the first frost in Tucson, AZ?

The average first fall frost (32°F) is December 9. There is a 1-in-10 chance of frost by November 21, so tender plants are at risk from that point on.

How long is the growing season in 85751?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 307 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 85751Tucson, AZ

The average last spring frost in Tucson is February 5 and the average first fall frost is December 9, giving a typical growing season of about 307 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Feb 5
Average first fall frost: Dec 9
Growing season: 307 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 3 · Feb 28 · Mar 24	Nov 11 · Nov 26 · Dec 14	271 days	100%
Frost / freeze (32°F)	Jan 4 · Feb 5 · Mar 2	Nov 21 · Dec 9 · Jan 3	307 days	99%
Hard freeze (28°F)	Dec 14 · Jan 11 · Feb 17	Nov 30 · Dec 26 · Feb 1	351 days	70%

Where these dates come from

ZIP code 85751 is matched to the NOAA station Tucson Intl Ap, AZ, 10.4 km away, at 2,549 ft elevation (69 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Tucson Intl Ap, AZ (used)	2,549 ft	Feb 5	Dec 9
Tucson Wfo, AZ	2,435 ft	Jan 20	Dec 17
Tucson Camp Ave Exp, AZ	2,330 ft	Feb 20	Nov 27
Tucson U Of A #1, AZ	2,315 ft	Feb 11	Dec 2

Frost dates near Tucson

Tucson, AZ 85702 · last Feb 5, first Dec 9
Mount Lemmon, AZ 85619 · last Mar 23, first Nov 22
Cortaro, AZ 85652 · last Feb 11, first Dec 2
Rillito, AZ 85654 · last Feb 11, first Dec 2
Marana, AZ 85658 · last Feb 11, first Dec 2
Sahuarita, AZ 85629 · last Feb 25, first Nov 27
Catalina, AZ 85738 · last Apr 2, first Nov 11
Vail, AZ 85641 · last Jan 26, first Dec 16

Frequently asked questions

When is the last frost in Tucson, AZ?: For ZIP code 85751, the average last spring frost (32°F) is February 5, based on NOAA 1991-2020 climate normals for the Tucson Intl Ap, AZ weather station. There is a 1-in-10 chance of a frost after March 2.
When is the first frost in Tucson, AZ?: The average first fall frost (32°F) is December 9. There is a 1-in-10 chance of frost by November 21, so tender plants are at risk from that point on.
How long is the growing season in 85751?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 307 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.