Deer Lodge, MT 59713 Frost Dates
Frost dates for Deer Lodge, MT, ZIP 59713
Typically, the last spring freeze lands around 06/09, roughly 285 days out. The first fall frost typically arrives around 09/08, about 91 frost-free days later.
The USDA Plant Hardiness Zone Map puts Deer Lodge in Zone 4b (-25 to -20°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 4b around Deer Lodge has about 2 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.
The actual range around Deer Lodge's last frost
06/09 is the middle of 30 years of NOAA records, not a promise. Plant by 05/23 and you're betting against frost in roughly 9 years out of 10. 06/26 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Deer Lodge compares
Deer Lodge's growing season runs about 91 days, ranking 39,896 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 333 of 392.
Learn more
local microclimates explains what one yard in Deer Lodge can differ from the 59713 normal, and zone vs. frost date explains why Zone 4b and Deer Lodge's frost date answer different questions.