Jordan, MT 59318 Frost Dates
Jordan, MT: when does the frost end?
Typically, the last spring freeze lands around 05/18, roughly 263 days out. Fall's first freeze usually shows up around 09/20, roughly 123 days after the last spring frost.
Jordan 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 3 weeks until Jordan'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
05/18 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/06 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/31 and only about 1 year in 10 sees frost after that.
Jordan against the rest of the dataset
Jordan's growing season runs about 123 days, ranking 38,918 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 197 of 392.
Learn more
Before leaning on 59318's figures: local microclimates explains what one yard in Jordan can differ from the 59318 normal, while zone vs. frost date explains why Zone 4b and Jordan's frost date answer different questions.