Richfield, ID 83349 Frost Dates
Frost dates for Richfield, ID, ZIP 83349
Typically, the last spring freeze lands around 04/24, roughly 239 days out. The first fall frost typically arrives around 10/16, about 173 frost-free days later.
The USDA Plant Hardiness Zone Map puts Richfield in Zone 6a (-10 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 6a around Richfield 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
04/24 is the middle of 30 years of NOAA records, not a promise. Plant by 04/09 and you're betting against frost in roughly 9 years out of 10. 05/12 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Richfield compares
Richfield's growing season runs about 173 days, ranking 28,053 of 40,283 US ZIP codes measured here, longest to shortest. Within ID, it ranks 54 of 320.
Learn more
local microclimates explains what one yard in Richfield can differ from the 83349 normal, and zone vs. frost date explains why Zone 6a and Richfield's frost date answer different questions.