Anchorage, AK 99510 Frost Dates
Frost dates for Anchorage, AK, ZIP 99510
Around 05/28 is the usual last spring frost, about 273 days away. The first fall frost typically arrives around 09/12, about 107 frost-free days later.
Anchorage sits in USDA Zone 5b (-15 to -10°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 5b 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.
The actual range around Anchorage's last frost
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 39,557 of 40,283 ZIP codes in this dataset. Within AK, it ranks 181 of 269.
Learn more
zone vs. frost date explains why Zone 5b 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.