Afton, WY 83110 Frost Dates
83110, near Afton, WY: the frost window
The last spring frost here typically falls around 06/20, about 296 days from today. Fall's first freeze usually shows up around 09/01, roughly 71 days after the last spring frost.
Afton sits in USDA Zone 5b (-15 to -10°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Afton's growing season runs out in roughly 1 week — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Afton's last frost
06/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 06/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 07/07 and only about 1 year in 10 sees frost after that.
Afton against the rest of the dataset
About 71 days separate Afton's last and first frost, putting it 40,108 of 40,283 ZIP codes nationally. Within WY, it ranks 163 of 192.
Learn more
Two guides worth reading on 83110: local microclimates, on what one yard in Afton can differ from the 83110 normal, and zone vs. frost date, on why Zone 5b and Afton's frost date answer different questions.