Glendale, AZ 85301 Frost Dates
Frost dates for Glendale, AZ, ZIP 85301
Typically, the last spring freeze lands around 01/20, roughly 145 days out. The first fall frost typically arrives around 12/15, about 331 frost-free days later.
The USDA Plant Hardiness Zone Map puts Glendale in Zone 9b (25 to 30°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 9b around Glendale 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 01/20 isn't a guarantee
01/20 is the middle of 30 years of NOAA records, not a promise. Plant by 02/18 and you're betting against frost in roughly 9 years out of 10. 12/23 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Glendale compares
Glendale's growing season runs about 331 days, ranking 2,916 of 40,283 US ZIP codes measured here, longest to shortest. Within AZ, it ranks 163 of 506.
Learn more
zone vs. frost date explains why Zone 9b and Glendale's frost date answer different questions, and the frost range explains how to read the range around Glendale's dates instead of trusting one.