Plummer, ID 83851 Frost Dates
Frost dates for Plummer, ID, ZIP 83851
Typically, the last spring freeze lands around 05/15, roughly 260 days out. The first fall frost typically arrives around 09/21, about 126 frost-free days later.
Plummer 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 Plummer 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 05/15 isn't a guarantee
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 Plummer compares
Plummer's growing season runs about 126 days, ranking 38,694 of 40,283 US ZIP codes measured here, longest to shortest. Within ID, it ranks 190 of 320.
Learn more
zone vs. frost date explains why Zone 6b and Plummer's frost date answer different questions, and the frost range explains how to read the range around Plummer's dates instead of trusting one.