Glenns Ferry, ID 83633 Frost Dates
Frost dates for Glenns Ferry, ID, ZIP 83633
Around 05/01 is the usual last spring frost, about 246 days away. The first fall frost typically arrives around 10/03, about 154 frost-free days later.
The USDA Plant Hardiness Zone Map puts Glenns Ferry in Zone 7a (0 to 5°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 7a around Glenns Ferry has about 5 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 Glenns Ferry's last frost
05/01 is the middle of 30 years of NOAA records, not a promise. Plant by 04/14 and you're betting against frost in roughly 9 years out of 10. 05/16 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Glenns Ferry compares
At roughly 154 frost-free days, Glenns Ferry places 34,360 of 40,283 ZIP codes in this dataset. Within ID, it ranks 102 of 320.
Learn more
zone vs. frost date explains why Zone 7a and Glenns Ferry's frost date answer different questions, and the frost range explains how to read the range around Glenns Ferry's dates instead of trusting one.