Phoenix, AZ 85012 Frost Dates
Frost dates for Phoenix, AZ, ZIP 85012
Typically, the last spring freeze lands around 01/05, roughly 130 days out. The first fall frost typically arrives around 01/03, about 365 frost-free days later.
Zone 10a (30 to 35°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 Phoenix, not a forecast for this year.
What to do before the first frost
Zone 10a around Phoenix has about 18 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 01/05 isn't a guarantee
01/05 is the middle of 30 years of NOAA records, not a promise. Plant by 01/22 and you're betting against frost in roughly 9 years out of 10. 12/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Phoenix compares
Phoenix's growing season runs about 365 days, ranking 9 of 40,283 US ZIP codes measured here, longest to shortest. Within AZ, it ranks 4 of 506.
Learn more
the frost range explains how to read the range around Phoenix's dates instead of trusting one, and local microclimates explains what one yard in Phoenix can differ from the 85012 normal.