South Tucson, AZ 85719 Frost Dates
South Tucson, AZ: when does the frost end?
Around 01/20 is the usual last spring frost, about 145 days away. Fall's first freeze usually shows up around 12/17, roughly 332 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts South Tucson in Zone 9b (25 to 30°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 16 weeks until South Tucson's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around South Tucson's last frost
01/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/18 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.
South Tucson against the rest of the dataset
At roughly 332 frost-free days, South Tucson places 2,896 of 40,283 ZIP codes in this dataset. Within AZ, it ranks 155 of 506.
Learn more
Before leaning on 85719's figures: zone vs. frost date explains why Zone 9b and South Tucson's frost date answer different questions, while the frost range explains how to read the range around South Tucson's dates instead of trusting one.