Jackson, WY 83025 Frost Dates
Jackson, WY: when does the frost end?
Typically, the last spring freeze lands around 06/20, roughly 296 days out. Fall's first freeze usually shows up around 08/31, roughly 70 days after the last spring frost.
Zone 4b (-25 to -20°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 Jackson, not a forecast for this year.
Stretching the season past the first frost
With roughly any day now until Jackson's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Jackson's last frost
06/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 06/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 07/09 and only about 1 year in 10 sees frost after that.
Jackson against the rest of the dataset
Jackson's growing season runs about 70 days, ranking 40,123 of 40,283 US ZIP codes measured here, longest to shortest. Within WY, it ranks 171 of 192.
Learn more
Before leaning on 83025's figures: the frost range explains how to read the range around Jackson's dates instead of trusting one, while local microclimates explains what one yard in Jackson can differ from the 83025 normal.