Bozeman, MT 59715 Frost Dates
Frost dates for Bozeman, MT, ZIP 59715
The last spring frost here typically falls around 05/26, about 271 days from today. The first fall frost typically arrives around 09/22, about 116 frost-free days later.
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.
What to do before the first frost
Zone 5a around Bozeman has about 4 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 05/26 isn't a guarantee
05/26 is the middle of 30 years of NOAA records, not a promise. Plant by 05/09 and you're betting against frost in roughly 9 years out of 10. 06/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Bozeman compares
At roughly 116 frost-free days, Bozeman places 39,270 of 40,283 ZIP codes in this dataset. Within MT, it ranks 238 of 392.
Learn more
the frost range explains how to read the range around Bozeman's dates instead of trusting one, and local microclimates explains what one yard in Bozeman can differ from the 59715 normal.