Wasilla, AK 99623 Frost Dates
Frost dates for Wasilla, AK, ZIP 99623
Typically, the last spring freeze lands around 05/16, roughly 261 days out. The first fall frost typically arrives around 09/23, about 128 frost-free days later.
Wasilla sits in USDA Zone 4b (-25 to -20°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 4b around Wasilla 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 05/16 isn't a guarantee
05/16 is the middle of 30 years of NOAA records, not a promise. Plant by 05/01 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 Wasilla compares
Wasilla's growing season runs about 128 days, ranking 38,533 of 40,283 US ZIP codes measured here, longest to shortest. Within AK, it ranks 79 of 269.
Learn more
zone vs. frost date explains why Zone 4b and Wasilla's frost date answer different questions, and the frost range explains how to read the range around Wasilla's dates instead of trusting one.