Anchorage, AK 99522 Frost Dates
99522, near Anchorage, AK: the frost window
Around 05/18 is the usual last spring frost, about 263 days away. Fall's first freeze usually shows up around 09/23, roughly 125 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Anchorage in Zone 5a (-20 to -15°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
Anchorage'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.
How much risk comes with planting early here
05/18 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/31 and only about 1 year in 10 sees frost after that.
Anchorage against the rest of the dataset
Anchorage's growing season runs about 125 days, ranking 38,742 of 40,283 US ZIP codes measured here, longest to shortest. Within AK, it ranks 91 of 269.
Learn more
Two guides worth reading on 99522: the frost range, on how to read the range around Anchorage's dates instead of trusting one, and local microclimates, on what one yard in Anchorage can differ from the 99522 normal.