Frost Dates for 99705 — North Pole, Alaska

Half of springs at N Pole 1N, AK see their last 32°F night by May 22; only one in ten is past it by May 12, and one in ten still has one after June 4. Planting tender crops after May 28 leaves a 30% risk of a frost on them, after May 31 20%, and after June 4 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 46% of the 37 Alaska stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 2 in half of years, as early as August 20 one year in ten, and holds off past September 17 one year in ten. A hard freeze of 28°F follows 12 days later, around September 14; in spring the one-in-ten date for 28°F is May 26, 9 days before the 32°F one. The freeze-free season lasts 102 days in a typical year, shorter than at 92% of the 37 Alaska stations; it reaches 119 days one year in ten and falls short of 83 one year in ten. On average 244 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 11 days longer, to about June 2, and return around August 22. Severe cold of 16°F or below comes every winter, usually between October 9 and April 18.

July is the warmest month at N Pole 1N, AK, averaging 71°F by day and 50°F at night; January is the coldest at -2°F and -17°F. A freezing night is all but certain in every month from September to May (a 90% chance or more). July is the only month with under a 10% chance of a 32°F night. In spring, June still brings one in 19% of years.

Warmth for growing adds up to 813 growing degree days a year (base 50°F), more than at 73% of the 37 Alaska stations. 39% of them (315) have built up by the end of June, and July adds the most, 329. Precipitation totals 13.7 inches a year, most in July (2.6") and least in March (0.4"); May to September bring 69% of it.

The nearest other station, Eielson Field, AK, 11 miles southeast of North Pole, has a last frost 2 days earlier (May 20), a first frost 1 day earlier (September 1), a season 2 days longer.

The first measurable snow (0.1 inch or more) in North Pole usually arrives around October 6, and the last of the season around April 24. Those are the middle dates across the winters of 1991–2020 at N Pole 1N, AK, 1.4 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 28 days after the last snow.

ZIP 99705 is 1 mile from N Pole 1N, AK, which stands at 496 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 99705 in zone 2a, the band where the coldest night of the year averaged -50 to -45°F (-45.6 to -42.8°C) over 1991–2020; a zone describes winter lows, not frost dates.