St. Maries, ID 83861 Frost Dates
Frost dates for St. Maries, ID, ZIP 83861
Around 05/15 is the usual last spring frost, about 260 days away. The first fall frost typically arrives around 09/21, about 126 frost-free days later.
The USDA Plant Hardiness Zone Map puts St. Maries in Zone 6b (-5 to 0°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 6b around St. Maries has about 3 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.
The actual range around St. Maries's last frost
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 06/02 is the safer bet, historically only a 1-in-10 chance of frost that late.
How St. Maries compares
About 126 days separate St. Maries's last and first frost, putting it 38,687 of 40,283 ZIP codes nationally. Within ID, it ranks 188 of 320.
Learn more
the frost range explains how to read the range around St. Maries's dates instead of trusting one, and local microclimates explains what one yard in St. Maries can differ from the 83861 normal.