Chefornak, AK 99622 Frost Dates
99622, near Chefornak, AK: the frost window
Around 05/21 is the usual last spring frost, about 266 days away. Fall's first freeze usually shows up around 09/22, roughly 122 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Chefornak in Zone 4a (-30 to -25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Chefornak's growing season runs out in roughly 4 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/21 isn't a guarantee
05/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/02 and only about 1 year in 10 sees frost after that.
Chefornak against the rest of the dataset
About 122 days separate Chefornak's last and first frost, putting it 38,968 of 40,283 ZIP codes nationally. Within AK, it ranks 117 of 269.
Learn more
Two guides worth reading on 99622: local microclimates, on what one yard in Chefornak can differ from the 99622 normal, and zone vs. frost date, on why Zone 4a and Chefornak's frost date answer different questions.