Bairoil, WY 82310 Frost Dates
Frost dates for Bairoil, WY, ZIP 82310
The last spring frost here typically falls around 06/01, about 277 days from today. The first fall frost typically arrives around 09/13, about 104 frost-free days later.
The USDA Plant Hardiness Zone Map puts Bairoil in Zone 4b (-25 to -20°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 4b around Bairoil has about 2 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 06/01 isn't a guarantee
06/01 is the middle of 30 years of NOAA records, not a promise. Plant by 05/17 and you're betting against frost in roughly 9 years out of 10. 06/16 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Bairoil compares
About 104 days separate Bairoil's last and first frost, putting it 39,619 of 40,283 ZIP codes nationally. Within WY, it ranks 137 of 192.
Learn more
local microclimates explains what one yard in Bairoil can differ from the 82310 normal, and zone vs. frost date explains why Zone 4b and Bairoil's frost date answer different questions.