FrostDateCheck

Tucson, AZ 85730 Frost Dates

Frost dates for Tucson, AZ, ZIP 85730

Zone 9a

Typically, the last spring freeze lands around 01/26, roughly 151 days out. The first fall frost typically arrives around 12/16, about 326 frost-free days later.

Zone 9a (20 to 25°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Tucson, not a forecast for this year.

What to do before the first frost

Zone 9a around Tucson has about 16 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.

Why 01/26 isn't a guarantee

01/26 is the middle of 30 years of NOAA records, not a promise. Plant by 02/25 and you're betting against frost in roughly 9 years out of 10. 12/24 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Tucson compares

About 326 days separate Tucson's last and first frost, putting it 3,205 of 40,283 ZIP codes nationally. Within AZ, it ranks 193 of 506.

Learn more

zone vs. frost date explains why Zone 9a and Tucson's frost date answer different questions, and the frost range explains how to read the range around Tucson's dates instead of trusting one.