Hot Springs, MT 59845 Frost Dates
When can you plant in Hot Springs, MT?
Around 05/15 is the usual last spring frost, about 260 days away. The first fall frost typically arrives around 09/28, about 134 frost-free days later.
Hot Springs sits in USDA Zone 6a (-10 to -5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
About 4 weeks of growing season left in Hot Springs before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/15 isn't a guarantee
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 05/03 and you're betting against frost in roughly 9 years out of 10. 06/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Hot Springs compares
Hot Springs's growing season runs about 134 days, ranking 38,004 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 112 of 392.
Learn more
the frost range covers how to read the range around Hot Springs's dates instead of trusting one. local microclimates covers what one yard in Hot Springs can differ from the 59845 normal.