Powell, WY 82440 Frost Dates
Powell, WY: when does the frost end?
Typically, the last spring freeze lands around 05/15, roughly 260 days out. Fall's first freeze usually shows up around 09/25, roughly 132 days after the last spring frost.
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 Powell, not a forecast for this year.
Stretching the season past the first frost
With roughly 4 weeks until Powell'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
05/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/01 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/01 and only about 1 year in 10 sees frost after that.
Powell against the rest of the dataset
At roughly 132 frost-free days, Powell places 38,184 of 40,283 ZIP codes in this dataset. Within WY, it ranks 59 of 192.
Learn more
Before leaning on 82440's figures: the frost range explains how to read the range around Powell's dates instead of trusting one, while local microclimates explains what one yard in Powell can differ from the 82440 normal.