Choteau, MT 59419 Frost Dates
When can you plant in Choteau, MT?
Around 06/09 is the usual last spring frost, about 285 days away. The first fall frost typically arrives around 09/03, about 86 frost-free days later.
The USDA Plant Hardiness Zone Map puts Choteau 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
About 1 week of growing season left in Choteau before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
06/09 is the middle of 30 years of NOAA records, not a promise. Plant by 05/25 and you're betting against frost in roughly 9 years out of 10. 07/02 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Choteau compares
About 86 days separate Choteau's last and first frost, putting it 39,976 of 40,283 ZIP codes nationally. Within MT, it ranks 348 of 392.
Learn more
zone vs. frost date covers why Zone 4b and Choteau's frost date answer different questions. the frost range covers how to read the range around Choteau's dates instead of trusting one.