Cheyenne, WY 82059 Frost Dates
Cheyenne, WY: when does the frost end?
Typically, the last spring freeze lands around 05/31, roughly 276 days out. Fall's first freeze usually shows up around 09/19, roughly 110 days after the last spring frost.
Zone 5b (-15 to -10°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 Cheyenne, not a forecast for this year.
Stretching the season past the first frost
With roughly 3 weeks until Cheyenne's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
05/31 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/15 and only about 1 year in 10 sees frost after that.
Cheyenne against the rest of the dataset
Cheyenne's growing season runs about 110 days, ranking 39,496 of 40,283 US ZIP codes measured here, longest to shortest. Within WY, it ranks 129 of 192.
Learn more
Before leaning on 82059's figures: local microclimates explains what one yard in Cheyenne can differ from the 82059 normal, while zone vs. frost date explains why Zone 5b and Cheyenne's frost date answer different questions.