Anchorage, AK 99523 Frost Dates
When can you plant in Anchorage, AK?
Around 05/18 is the usual last spring frost, about 263 days away. The first fall frost typically arrives around 09/23, about 125 frost-free days later.
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.
What to do before the first frost
About 4 weeks of growing season left in Anchorage before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Anchorage's last frost
05/18 is the middle of 30 years of NOAA records, not a promise. Plant by 05/04 and you're betting against frost in roughly 9 years out of 10. 05/31 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Anchorage compares
Anchorage's growing season runs about 125 days, ranking 38,743 of 40,283 US ZIP codes measured here, longest to shortest. Within AK, it ranks 92 of 269.
Learn more
local microclimates covers what one yard in Anchorage can differ from the 99523 normal. zone vs. frost date covers why Zone 5a and Anchorage's frost date answer different questions.