Afton, WY 83119 Frost Dates
When can you plant in Afton, WY?
The last spring frost here typically falls around 06/20, about 296 days from today. The first fall frost typically arrives around 09/01, about 71 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 Afton, not a forecast for this year.
What to do before the first frost
About 1 week of growing season left in Afton before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
06/20 is the middle of 30 years of NOAA records, not a promise. Plant by 06/02 and you're betting against frost in roughly 9 years out of 10. 07/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Afton compares
Afton's growing season runs about 71 days, ranking 40,110 of 40,283 US ZIP codes measured here, longest to shortest. Within WY, it ranks 165 of 192.
Learn more
local microclimates covers what one yard in Afton can differ from the 83119 normal. zone vs. frost date covers why Zone 5a and Afton's frost date answer different questions.