Phoenix, AZ 85004 Frost Dates
Phoenix, AZ: when does the frost end?
Typically, the last spring freeze lands around 01/05, roughly 130 days out. Fall's first freeze usually shows up around 01/03, roughly 365 days after the last spring frost.
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.
Stretching the season past the first frost
With roughly 18 weeks until Phoenix's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 01/05 isn't a guarantee
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
At roughly 365 frost-free days, Phoenix places 7 of 40,283 ZIP codes in this dataset. Within AZ, it ranks 2 of 506.
Learn more
Before leaning on 85004's figures: the frost range explains how to read the range around Phoenix's dates instead of trusting one, while local microclimates explains what one yard in Phoenix can differ from the 85004 normal.