Altamont, UT 84073 Frost Dates
84073, near Altamont, UT: the frost window
Around 05/31 is the usual last spring frost, about 276 days away. Fall's first freeze usually shows up around 09/23, roughly 112 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Altamont in Zone 6a (-10 to -5°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
Altamont's growing season runs out in roughly 4 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/31 isn't a guarantee
05/31 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/16 and only about 1 year in 10 sees frost after that.
Altamont against the rest of the dataset
At roughly 112 frost-free days, Altamont places 39,441 of 40,283 ZIP codes in this dataset. Within UT, it ranks 324 of 344.
Learn more
Two guides worth reading on 84073: local microclimates, on what one yard in Altamont can differ from the 84073 normal, and zone vs. frost date, on why Zone 6a and Altamont's frost date answer different questions.