Anchorage, AK 99511 Frost Dates
Anchorage, AK: when does the frost end?
Typically, the last spring freeze lands around 05/12, roughly 257 days out. Fall's first freeze usually shows up around 09/26, roughly 137 days after the last spring frost.
Anchorage sits in USDA Zone 5a (-20 to -15°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 4 weeks until Anchorage's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Anchorage's last frost
05/12 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/24 and only about 1 year in 10 sees frost after that.
Anchorage against the rest of the dataset
About 137 days separate Anchorage's last and first frost, putting it 37,494 of 40,283 ZIP codes nationally. Within AK, it ranks 70 of 269.
Learn more
Before leaning on 99511's figures: zone vs. frost date explains why Zone 5a and Anchorage's frost date answer different questions, while the frost range explains how to read the range around Anchorage's dates instead of trusting one.