Townsend, MT 59643 Frost Dates
When can you plant in Townsend, MT?
Typically, the last spring freeze lands around 05/19, roughly 264 days out. The first fall frost typically arrives around 09/19, about 122 frost-free days later.
The USDA Plant Hardiness Zone Map puts Townsend in Zone 5a (-20 to -15°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 Townsend before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/19 isn't a guarantee
05/19 is the middle of 30 years of NOAA records, not a promise. Plant by 05/08 and you're betting against frost in roughly 9 years out of 10. 06/02 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Townsend compares
Townsend's growing season runs about 122 days, ranking 38,939 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 201 of 392.
Learn more
the frost range covers how to read the range around Townsend's dates instead of trusting one. local microclimates covers what one yard in Townsend can differ from the 59643 normal.