Belt, MT 59469 Frost Dates
Belt, MT: when does the frost end?
Around 05/22 is the usual last spring frost, about 267 days away. Fall's first freeze usually shows up around 09/23, roughly 123 days after the last spring frost.
Belt sits in USDA Zone 4b (-25 to -20°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 Belt's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Belt's last frost
05/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/09 and only about 1 year in 10 sees frost after that.
Belt against the rest of the dataset
About 123 days separate Belt's last and first frost, putting it 38,915 of 40,283 ZIP codes nationally. Within MT, it ranks 196 of 392.
Learn more
Before leaning on 59469's figures: the frost range explains how to read the range around Belt's dates instead of trusting one, while local microclimates explains what one yard in Belt can differ from the 59469 normal.