FrostDateCheck

White Mountain, AK 99784 Frost Dates

When can you plant in White Mountain, AK?

Zone 4a

The last spring frost here typically falls around 06/05, about 281 days from today. The first fall frost typically arrives around 09/03, about 88 frost-free days later.

Zone 4a (-30 to -25°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for White Mountain, not a forecast for this year.

What to do before the first frost

About 1 week of growing season left in White Mountain before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

Why 06/05 isn't a guarantee

06/05 is the middle of 30 years of NOAA records, not a promise. Plant by 05/20 and you're betting against frost in roughly 9 years out of 10. 06/26 is the safer bet, historically only a 1-in-10 chance of frost that late.

How White Mountain compares

At roughly 88 frost-free days, White Mountain places 39,961 of 40,283 ZIP codes in this dataset. Within AK, it ranks 236 of 269.

Learn more

the frost range covers how to read the range around White Mountain's dates instead of trusting one. local microclimates covers what one yard in White Mountain can differ from the 99784 normal.