Frost Dates for 56401 — Brainerd, Minnesota

Half of springs at Brainerd, MN see their last 32°F night by May 8; only one in ten is past it by April 28, and one in ten still has one after May 21. Planting tender crops after May 13 leaves a 30% risk of a frost on them, after May 16 20%, and after May 21 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 61% of the 142 Minnesota stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 29 in half of years, as early as September 16 one year in ten, and holds off past October 11 one year in ten. A hard freeze of 28°F follows 9 days later, around October 8; in spring the one-in-ten date for 28°F is May 11, 10 days before the 32°F one. The freeze-free season lasts 141 days in a typical year, shorter than at 75% of the 142 Minnesota stations; it reaches 159 days one year in ten and falls short of 125 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 19, and return around September 20. Severe cold of 16°F or below comes every winter, usually between November 9 and April 4.

July is the warmest month at Brainerd, MN, averaging 80°F by day and 58°F at night; January is the coldest at 20°F and -2°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 82% of years.

Warmth for growing adds up to 2,084 growing degree days a year (base 50°F), fewer than at 76% of the 142 Minnesota stations. 32% of them (661) have built up by the end of June, and July adds the most, 587. Precipitation totals 30.6 inches a year, most in June (4.6") and least in January (0.8"); May to September bring 64% of it.

The nearest other station, Brainerd Crow Wing Co Airport, MN, 4 miles northeast of Brainerd, has a last frost 5 days later (May 13), a first frost 2 days earlier (September 27), a season 3 days shorter.

The first measurable snow (0.1 inch or more) in Brainerd usually arrives around November 10, and the last of the season around April 11. Those are the middle dates across the winters of 1991–2020 at Brainerd, MN, 2.3 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 27 days after the last snow.

ZIP 56401 is 2 miles from Brainerd, MN, which stands at 1,180 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 56401 in zone 4a, the band where the coldest night of the year averaged -30 to -25°F (-34.4 to -31.7°C) over 1991–2020; a zone describes winter lows, not frost dates.