Nashua, MT 59248 Frost Dates
Nashua, MT: when does the frost end?
Typically, the last spring freeze lands around 05/12, roughly 257 days out. Fall's first freeze usually shows up around 09/24, roughly 134 days after the last spring frost.
Nashua sits in USDA Zone 4a (-30 to -25°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.
Stretching the season past the first frost
With roughly 4 weeks until Nashua's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/12 isn't a guarantee
05/12 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/26 and only about 1 year in 10 sees frost after that.
Nashua against the rest of the dataset
Nashua's growing season runs about 134 days, ranking 38,017 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 115 of 392.
Learn more
Before leaning on 59248's figures: zone vs. frost date explains why Zone 4a and Nashua's frost date answer different questions, while the frost range explains how to read the range around Nashua's dates instead of trusting one.