Lodge Grass, MT 59075 Frost Dates
59075, near Lodge Grass, MT: the frost window
Around 05/07 is the usual last spring frost, about 252 days away. Fall's first freeze usually shows up around 10/05, roughly 151 days after the last spring frost.
Zone 5a (-20 to -15°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 Lodge Grass, not a forecast for this year.
Stretching the season past the first frost
Lodge Grass's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/07 isn't a guarantee
05/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/20 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/24 and only about 1 year in 10 sees frost after that.
Lodge Grass against the rest of the dataset
Lodge Grass's growing season runs about 151 days, ranking 35,145 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 19 of 392.
Learn more
Two guides worth reading on 59075: the frost range, on how to read the range around Lodge Grass's dates instead of trusting one, and local microclimates, on what one yard in Lodge Grass can differ from the 59075 normal.