Hot Springs, MT 59848 Frost Dates
59848, near Hot Springs, MT: the frost window
Around 05/15 is the usual last spring frost, about 260 days away. Fall's first freeze usually shows up around 09/28, roughly 134 days after the last spring frost.
Zone 6a (-10 to -5°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Hot Springs, not a forecast for this year.
Stretching the season past the first frost
Hot Springs's growing season runs out in roughly 4 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Hot Springs's last frost
05/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/03 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/01 and only about 1 year in 10 sees frost after that.
Hot Springs against the rest of the dataset
At roughly 134 frost-free days, Hot Springs places 38,005 of 40,283 ZIP codes in this dataset. Within MT, it ranks 113 of 392.
Learn more
Two guides worth reading on 59848: local microclimates, on what one yard in Hot Springs can differ from the 59848 normal, and zone vs. frost date, on why Zone 6a and Hot Springs's frost date answer different questions.