Anchorage, AK 99507 Frost Dates
Frost dates for Anchorage, AK, ZIP 99507
The last spring frost here typically falls around 05/28, about 273 days from today. The first fall frost typically arrives around 09/12, about 107 frost-free days later.
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.
What to do before the first frost
Zone 5a around Anchorage has about 2 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.
How much risk comes with planting early here
05/28 is the middle of 30 years of NOAA records, not a promise. Plant by 05/17 and you're betting against frost in roughly 9 years out of 10. 06/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Anchorage compares
At roughly 107 frost-free days, Anchorage places 39,556 of 40,283 ZIP codes in this dataset. Within AK, it ranks 180 of 269.
Learn more
zone vs. frost date explains why Zone 5a and Anchorage's frost date answer different questions, and the frost range explains how to read the range around Anchorage's dates instead of trusting one.