Anchorage, AK 99514 Frost Dates
Frost dates for Anchorage, AK, ZIP 99514
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
Zone 5a around Anchorage has about 4 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 05/18 isn't a guarantee
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 38,738 of 40,283 US ZIP codes measured here, longest to shortest. Within AK, it ranks 87 of 269.
Learn more
local microclimates explains what one yard in Anchorage can differ from the 99514 normal, and zone vs. frost date explains why Zone 5a and Anchorage's frost date answer different questions.