Post Falls, ID 83854 Frost Dates
Frost dates for Post Falls, ID, ZIP 83854
Typically, the last spring freeze lands around 04/22, roughly 237 days out. The first fall frost typically arrives around 10/18, about 179 frost-free days later.
Post Falls sits in USDA Zone 6b (-5 to 0°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 6b around Post Falls has about 7 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
04/22 is the middle of 30 years of NOAA records, not a promise. Plant by 04/04 and you're betting against frost in roughly 9 years out of 10. 05/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Post Falls compares
Post Falls's growing season runs about 179 days, ranking 25,154 of 40,283 US ZIP codes measured here, longest to shortest. Within ID, it ranks 20 of 320.
Learn more
the frost range explains how to read the range around Post Falls's dates instead of trusting one, and local microclimates explains what one yard in Post Falls can differ from the 83854 normal.