Wickenburg, AZ 85390 Frost Dates
85390, near Wickenburg, AZ: the frost window
The last spring frost here typically falls around 03/07, about 191 days from today. Fall's first freeze usually shows up around 11/20, roughly 254 days after the last spring frost.
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 Wickenburg, not a forecast for this year.
Stretching the season past the first frost
Wickenburg's growing season runs out in roughly 12 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 03/07 isn't a guarantee
03/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/08 and only about 1 year in 10 sees frost after that.
Wickenburg against the rest of the dataset
At roughly 254 frost-free days, Wickenburg places 7,023 of 40,283 ZIP codes in this dataset. Within AZ, it ranks 316 of 506.
Learn more
Two guides worth reading on 85390: the frost range, on how to read the range around Wickenburg's dates instead of trusting one, and local microclimates, on what one yard in Wickenburg can differ from the 85390 normal.