Glasgow, MT 59273 Frost Dates
Glasgow, MT: when does the frost end?
The last spring frost here typically falls around 05/13, about 258 days from today. Fall's first freeze usually shows up around 09/27, roughly 134 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Glasgow in Zone 4a (-30 to -25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 4 weeks until Glasgow's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
05/13 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/02 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.
Glasgow against the rest of the dataset
About 134 days separate Glasgow's last and first frost, putting it 37,964 of 40,283 ZIP codes nationally. Within MT, it ranks 111 of 392.
Learn more
Before leaning on 59273's figures: zone vs. frost date explains why Zone 4a and Glasgow's frost date answer different questions, while the frost range explains how to read the range around Glasgow's dates instead of trusting one.