Anchorage, AK 99530 Frost Dates
When can you plant in Anchorage, AK?
Typically, the last spring freeze lands around 05/01, roughly 246 days out. The first fall frost typically arrives around 09/29, about 150 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
About 5 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.
Why 05/01 isn't a guarantee
05/01 is the middle of 30 years of NOAA records, not a promise. Plant by 04/19 and you're betting against frost in roughly 9 years out of 10. 05/09 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Anchorage compares
At roughly 150 frost-free days, Anchorage places 35,239 of 40,283 ZIP codes in this dataset. Within AK, it ranks 51 of 269.
Learn more
zone vs. frost date covers why Zone 5b and Anchorage's frost date answer different questions. the frost range covers how to read the range around Anchorage's dates instead of trusting one.