Gillette, WY 82717 Frost Dates
Gillette, WY: when does the frost end?
Around 05/22 is the usual last spring frost, about 267 days away. Fall's first freeze usually shows up around 09/25, roughly 125 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Gillette 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
With roughly 4 weeks until Gillette's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
05/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/04 and only about 1 year in 10 sees frost after that.
Gillette against the rest of the dataset
Gillette's growing season runs about 125 days, ranking 38,747 of 40,283 US ZIP codes measured here, longest to shortest. Within WY, it ranks 78 of 192.
Learn more
Before leaning on 82717's figures: the frost range explains how to read the range around Gillette's dates instead of trusting one, while local microclimates explains what one yard in Gillette can differ from the 82717 normal.