Frost Dates for 56331 — Freeport, Minnesota

Half of springs at Melrose, MN see their last 32°F night by May 4; only one in ten is past it by April 22, and one in ten still has one after May 19. Planting tender crops after May 10 leaves a 30% risk of a frost on them, after May 13 20%, and after May 19 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 17 one year in ten, and holds off past October 15 one year in ten. A hard freeze of 28°F follows 11 days later, around October 12; in spring the one-in-ten date for 28°F is May 8, 11 days before the 32°F one. The freeze-free season lasts 148 days in a typical year, shorter than at 59% of the 142 Minnesota stations; it reaches 165 days one year in ten and falls short of 129 one year in ten. On average 175 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 May 14, and return around September 23. Severe cold of 16°F or below comes every winter, usually between November 8 and April 2.

July is the warmest month at Melrose, MN, averaging 81°F by day and 60°F at night; January is the coldest at 20°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 66% of years.

Warmth for growing adds up to 2,305 growing degree days a year (base 50°F), fewer than at 61% of the 142 Minnesota stations. 33% of them (755) have built up by the end of June, and July adds the most, 634. Precipitation totals 29.0 inches a year, most in July (4.3") and least in January (0.7"); May to September bring 64% of it.

The nearest other station, Collegeville St John'S, MN, 15 miles southeast of Freeport, has a last frost 1 day earlier (May 3), a first frost 6 days later (October 7), a season 7 days longer.

The first measurable snow (0.1 inch or more) in Freeport usually arrives around November 15, and the last of the season around April 10. Those are the middle dates across the winters of 1991–2020 at Melrose, MN, 6.2 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 24 days after the last snow.

ZIP 56331 is 6 miles from Melrose, MN, which stands at 1,195 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 56378 (Sauk Centre). The 2023 USDA Plant Hardiness Zone Map lists ZIP 56331 in zone 4b, the band where the coldest night of the year averaged -25 to -20°F (-31.7 to -28.9°C) over 1991–2020; a zone describes winter lows, not frost dates.