Oro Valley, AZ 85755 Frost Dates
85755, near Oro Valley, AZ: the frost window
Typically, the last spring freeze lands around 02/26, roughly 182 days out. Fall's first freeze usually shows up around 12/04, roughly 279 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 Oro Valley, not a forecast for this year.
Stretching the season past the first frost
Oro Valley's growing season runs out in roughly 14 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Oro Valley's last frost
02/26 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/29 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/18 and only about 1 year in 10 sees frost after that.
Oro Valley against the rest of the dataset
At roughly 279 frost-free days, Oro Valley places 4,865 of 40,283 ZIP codes in this dataset. Within AZ, it ranks 296 of 506.
Learn more
Two guides worth reading on 85755: zone vs. frost date, on why Zone 9a and Oro Valley's frost date answer different questions, and the frost range, on how to read the range around Oro Valley's dates instead of trusting one.