Mills, WY 82630 Frost Dates
Frost dates for Mills, WY, ZIP 82630
The last spring frost here typically falls around 05/30, about 275 days from today. The first fall frost typically arrives around 09/22, about 115 frost-free days later.
Zone 5a (-20 to -15°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Mills, not a forecast for this year.
What to do before the first frost
Zone 5a around Mills has about 4 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
05/30 is the middle of 30 years of NOAA records, not a promise. Plant by 05/12 and you're betting against frost in roughly 9 years out of 10. 06/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Mills compares
About 115 days separate Mills's last and first frost, putting it 39,307 of 40,283 ZIP codes nationally. Within WY, it ranks 118 of 192.
Learn more
the frost range explains how to read the range around Mills's dates instead of trusting one, and local microclimates explains what one yard in Mills can differ from the 82630 normal.