Phoenix, AZ 85015 Frost Dates
85015, near Phoenix, AZ: the frost window
The last spring frost here typically falls around 01/05, about 130 days from today. Fall's first freeze usually shows up around 01/03, roughly 365 days after the last spring frost.
Phoenix sits in USDA Zone 9b (25 to 30°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Phoenix's growing season runs out in roughly 18 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
01/05 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/19 and only about 1 year in 10 sees frost after that.
Phoenix against the rest of the dataset
About 365 days separate Phoenix's last and first frost, putting it 12 of 40,283 ZIP codes nationally. Within AZ, it ranks 7 of 506.
Learn more
Two guides worth reading on 85015: local microclimates, on what one yard in Phoenix can differ from the 85015 normal, and zone vs. frost date, on why Zone 9b and Phoenix's frost date answer different questions.