Jordan, MT 59337 Frost Dates
When can you plant in Jordan, MT?
Around 05/18 is the usual last spring frost, about 263 days away. The first fall frost typically arrives around 09/20, about 123 frost-free days later.
The USDA Plant Hardiness Zone Map puts Jordan in Zone 4a (-30 to -25°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 3 weeks of growing season left in Jordan before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/18 isn't a guarantee
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. 05/31 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Jordan compares
About 123 days separate Jordan's last and first frost, putting it 38,919 of 40,283 ZIP codes nationally. Within MT, it ranks 198 of 392.
Learn more
zone vs. frost date covers why Zone 4a and Jordan's frost date answer different questions. the frost range covers how to read the range around Jordan's dates instead of trusting one.