Billings, MT 59002 Frost Dates
Billings, MT: when does the frost end?
Typically, the last spring freeze lands around 05/04, roughly 249 days out. Fall's first freeze usually shows up around 10/07, roughly 156 days after the last spring frost.
Billings sits in USDA Zone 5a (-20 to -15°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 6 weeks until Billings's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Billings's last frost
05/04 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 05/18 and only about 1 year in 10 sees frost after that.
Billings against the rest of the dataset
About 156 days separate Billings's last and first frost, putting it 33,488 of 40,283 ZIP codes nationally. Within MT, it ranks 10 of 392.
Learn more
Before leaning on 59002's figures: local microclimates explains what one yard in Billings can differ from the 59002 normal, while zone vs. frost date explains why Zone 5a and Billings's frost date answer different questions.