St. Anthony, ID 83445 Frost Dates
Frost dates for St. Anthony, ID, ZIP 83445
The last spring frost here typically falls around 05/29, about 274 days from today. The first fall frost typically arrives around 09/13, about 106 frost-free days later.
St. Anthony 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.
What to do before the first frost
Zone 5a around St. Anthony has about 2 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
05/29 is the middle of 30 years of NOAA records, not a promise. Plant by 05/12 and you're betting against frost in roughly 9 years out of 10. 06/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How St. Anthony compares
St. Anthony's growing season runs about 106 days, ranking 39,580 of 40,283 US ZIP codes measured here, longest to shortest. Within ID, it ranks 248 of 320.
Learn more
zone vs. frost date explains why Zone 5a and St. Anthony's frost date answer different questions, and the frost range explains how to read the range around St. Anthony's dates instead of trusting one.