Anchorage, AK 99515 Frost Dates
Anchorage, AK: when does the frost end?
Around 05/05 is the usual last spring frost, about 250 days away. Fall's first freeze usually shows up around 09/29, roughly 147 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
With roughly 5 weeks until Anchorage'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
05/05 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.
Anchorage against the rest of the dataset
At roughly 147 frost-free days, Anchorage places 35,823 of 40,283 ZIP codes in this dataset. Within AK, it ranks 56 of 269.
Learn more
Before leaning on 99515's figures: the frost range explains how to read the range around Anchorage's dates instead of trusting one, while local microclimates explains what one yard in Anchorage can differ from the 99515 normal.