Frost Dates for 99752 — Kotzebue, Alaska

Half of springs at Kotzebue Ralph Wein Airport, AK see their last 32°F night by June 5; only one in ten is past it by May 20, and one in ten still has one after June 17. Planting tender crops after June 10 leaves a 30% risk of a frost on them, after June 13 20%, and after June 17 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 65% of the 37 Alaska stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 24 in half of years, as early as September 7 one year in ten, and holds off past October 6 one year in ten. A hard freeze of 28°F follows 9 days later, around October 3; in spring the one-in-ten date for 28°F is June 7, 10 days before the 32°F one. The freeze-free season lasts 110 days in a typical year, shorter than at 81% of the 37 Alaska stations; it reaches 128 days one year in ten and falls short of 87 one year in ten. On average 236 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 10 days longer, to about June 15, and return around September 12. Severe cold of 16°F or below comes every winter, usually between October 22 and May 6.

July is the warmest month at Kotzebue Ralph Wein Airport, AK, averaging 60°F by day and 51°F at night; January is the coldest at 5°F and -8°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 71% of years.

Warmth for growing adds up to 372 growing degree days a year (base 50°F), fewer than at 92% of the 37 Alaska stations. 19% of them (71) have built up by the end of June, and July adds the most, 182. Precipitation totals 11.3 inches a year, most in August (2.1") and least in May (0.4"); May to September bring 54% of it.

The first measurable snow (0.1 inch or more) in Kotzebue usually arrives around October 1, and the last of the season around May 8. Those are the middle dates across the winters of 1991–2020 at Kotzebue Ralph Wein Airport, AK, 2.5 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 99752 is 3 miles from Kotzebue Ralph Wein Airport, AK, which stands at 30 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 99752 in zone 2b, the band where the coldest night of the year averaged -45 to -40°F (-42.8 to -40.0°C) over 1991–2020; a zone describes winter lows, not frost dates.