Frost Dates for 56465 — Merrifield, Minnesota

Half of springs at Brainerd Crow Wing Co Airport, MN see their last 32°F night by May 13; only one in ten is past it by April 29, and one in ten still has one after May 27. Planting tender crops after May 19 leaves a 30% risk of a frost on them, after May 23 20%, and after May 27 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 37% of the 142 Minnesota stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 27 in half of years, as early as September 14 one year in ten, and holds off past October 12 one year in ten. A hard freeze of 28°F follows 11 days later, around October 8; in spring the one-in-ten date for 28°F is May 17, 10 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 157 days one year in ten and falls short of 117 one year in ten. On average 173 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 24, and return around September 19. Severe cold of 16°F or below comes every winter, usually between November 9 and April 4.

July is the warmest month at Brainerd Crow Wing Co Airport, MN, averaging 82°F by day and 58°F at night; January is the coldest at 21°F and 0°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 85% of years.

Warmth for growing adds up to 2,187 growing degree days a year (base 50°F), fewer than at 67% of the 142 Minnesota stations. 32% of them (701) have built up by the end of June, and July adds the most, 607. Precipitation totals 24.8 inches a year, most in July (4.4") and least in February (0.4"); May to September bring 70% of it.

The nearest other station, Pine Rvr Dam, MN, 10 miles north of Merrifield, has a last frost 7 days earlier (May 6), a first frost 10 days later (October 7), a season 14 days longer.

The first measurable snow (0.1 inch or more) in Merrifield usually arrives around November 13, and the last of the season around April 1. Those are the middle dates across the winters of 1991–2020 at Pine Rvr Dam, MN, 9.8 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 42 days after the last snow.

ZIP 56465 is 9 miles from Brainerd Crow Wing Co Airport, MN, which stands at 1,221 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 56444 (Deerwood). The 2023 USDA Plant Hardiness Zone Map lists ZIP 56465 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.