Frost Dates for 56636 — Deer River, Minnesota

Half of springs at Pokegama Dam, MN see their last 32°F night by May 16; only one in ten is past it by May 1, and one in ten still has one after May 31. Planting tender crops after May 23 leaves a 30% risk of a frost on them, after May 26 20%, and after May 31 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 64% of the 142 Minnesota stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 1 in half of years, as early as September 18 one year in ten, and holds off past October 12 one year in ten. A hard freeze of 28°F follows 9 days later, around October 10; in spring the one-in-ten date for 28°F is May 19, 12 days before the 32°F one. The freeze-free season lasts 138 days in a typical year, shorter than at 81% of the 142 Minnesota stations; it reaches 155 days one year in ten and falls short of 117 one year in ten. On average 185 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 May 27, and return around September 22. Severe cold of 16°F or below comes every winter, usually between November 9 and April 5.

July is the warmest month at Pokegama Dam, MN, averaging 78°F by day and 57°F at night; January is the coldest at 18°F and -3°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 90% of years.

Warmth for growing adds up to 1,865 growing degree days a year (base 50°F), fewer than at 88% of the 142 Minnesota stations. 30% of them (559) have built up by the end of June, and July adds the most, 539. Precipitation totals 27.7 inches a year, most in June (4.6") and least in February (0.7"); May to September bring 66% of it.

The nearest other station, Grand Rpds Forest Lab, MN, 19 miles southeast of Deer River, has a last frost 1 day later (May 17), a first frost 7 days earlier (September 24), a season 8 days shorter.

The first measurable snow (0.1 inch or more) in Deer River usually arrives around November 8, and the last of the season around April 8. Those are the middle dates across the winters of 1991–2020 at Pokegama Dam, MN, 15.3 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 38 days after the last snow.

ZIP 56636 is 15 miles from Pokegama Dam, MN, which stands at 1,280 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 56636 in zone 3b, the band where the coldest night of the year averaged -35 to -30°F (-37.2 to -34.4°C) over 1991–2020; a zone describes winter lows, not frost dates.