Bozeman, MT 59718 Frost Dates
Bozeman, MT: when does the frost end?
Around 05/23 is the usual last spring frost, about 268 days away. Fall's first freeze usually shows up around 09/23, roughly 123 days after the last spring frost.
Bozeman sits in USDA Zone 5a (-20 to -15°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 4 weeks until Bozeman's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Bozeman's last frost
05/23 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/12 and only about 1 year in 10 sees frost after that.
Bozeman against the rest of the dataset
Bozeman's growing season runs about 123 days, ranking 38,878 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 193 of 392.
Learn more
Before leaning on 59718's figures: the frost range explains how to read the range around Bozeman's dates instead of trusting one, while local microclimates explains what one yard in Bozeman can differ from the 59718 normal.