Hartville, WY 82215 Frost Dates
82215, near Hartville, WY: the frost window
Around 05/11 is the usual last spring frost, about 256 days away. Fall's first freeze usually shows up around 10/03, roughly 144 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Hartville in Zone 5a (-20 to -15°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
Hartville's growing season runs out in roughly 5 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 Hartville's last frost
05/11 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/29 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/25 and only about 1 year in 10 sees frost after that.
Hartville against the rest of the dataset
Hartville's growing season runs about 144 days, ranking 36,478 of 40,283 US ZIP codes measured here, longest to shortest. Within WY, it ranks 13 of 192.
Learn more
Two guides worth reading on 82215: zone vs. frost date, on why Zone 5a and Hartville's frost date answer different questions, and the frost range, on how to read the range around Hartville's dates instead of trusting one.