Lavina, MT 59046 Frost Dates
Frost dates for Lavina, MT, ZIP 59046
Around 05/17 is the usual last spring frost, about 262 days away. The first fall frost typically arrives around 09/23, about 127 frost-free days later.
Lavina 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.
What to do before the first frost
Zone 4b around Lavina has about 4 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
05/17 is the middle of 30 years of NOAA records, not a promise. Plant by 05/03 and you're betting against frost in roughly 9 years out of 10. 05/30 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Lavina compares
At roughly 127 frost-free days, Lavina places 38,666 of 40,283 ZIP codes in this dataset. Within MT, it ranks 157 of 392.
Learn more
the frost range explains how to read the range around Lavina's dates instead of trusting one, and local microclimates explains what one yard in Lavina can differ from the 59046 normal.