Clark Fork, ID 83811 Frost Dates
Frost dates for Clark Fork, ID, ZIP 83811
The last spring frost here typically falls around 05/20, about 265 days from today. The first fall frost typically arrives around 09/20, about 119 frost-free days later.
Clark Fork 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 Clark Fork 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.
Why 05/20 isn't a guarantee
05/20 is the middle of 30 years of NOAA records, not a promise. Plant by 05/04 and you're betting against frost in roughly 9 years out of 10. 06/05 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Clark Fork compares
At roughly 119 frost-free days, Clark Fork places 39,158 of 40,283 ZIP codes in this dataset. Within ID, it ranks 222 of 320.
Learn more
the frost range explains how to read the range around Clark Fork's dates instead of trusting one, and local microclimates explains what one yard in Clark Fork can differ from the 83811 normal.