Miles City, MT 59351 Frost Dates
When can you plant in Miles City, MT?
The last spring frost here typically falls around 05/18, about 263 days from today. The first fall frost typically arrives around 09/22, about 126 frost-free days later.
Zone 4b (-25 to -20°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Miles City, not a forecast for this year.
What to do before the first frost
About 4 weeks of growing season left in Miles City before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Miles City's last frost
05/18 is the middle of 30 years of NOAA records, not a promise. Plant by 05/06 and you're betting against frost in roughly 9 years out of 10. 05/30 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Miles City compares
Miles City's growing season runs about 126 days, ranking 38,683 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 159 of 392.
Learn more
local microclimates covers what one yard in Miles City can differ from the 59351 normal. zone vs. frost date covers why Zone 4b and Miles City's frost date answer different questions.