Frost Dates for 56461 — Laporte, Minnesota

Half of springs at Cass Lake, MN see their last 32°F night by May 17; only one in ten is past it by May 3, and one in ten still has one after May 30. Planting tender crops after May 22 leaves a 30% risk of a frost on them, after May 25 20%, and after May 30 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 26 in half of years, as early as September 12 one year in ten, and holds off past October 11 one year in ten. A hard freeze of 28°F follows 10 days later, around October 6; in spring the one-in-ten date for 28°F is May 20, 10 days before the 32°F one. The freeze-free season lasts 131 days in a typical year, shorter than at 92% of the 142 Minnesota stations; it reaches 149 days one year in ten and falls short of 112 one year in ten. On average 187 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 28, and return around September 17. Severe cold of 16°F or below comes every winter, usually between November 6 and April 8.

July is the warmest month at Cass Lake, MN, averaging 79°F by day and 58°F at night; January is the coldest at 18°F and -4°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month.

Warmth for growing adds up to 2,027 growing degree days a year (base 50°F), fewer than at 79% of the 142 Minnesota stations. 31% of them (635) have built up by the end of June, and July adds the most, 575. Precipitation totals 26.5 inches a year, most in June (4.1") and least in February (0.7"); May to September bring 63% of it.

The nearest other station, Walker, MN, 17 miles southeast of Laporte, has a last frost 13 days earlier (May 4), a first frost 11 days later (October 7), a season 24 days longer.

The first measurable snow (0.1 inch or more) in Laporte usually arrives around October 29, and the last of the season around April 16. Those are the middle dates across the winters of 1991–2020 at Cass Lake, MN, 13.8 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 31 days after the last snow.

ZIP 56461 is 14 miles from Cass Lake, MN, which stands at 1,296 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 56601 (Bemidji). The 2023 USDA Plant Hardiness Zone Map lists ZIP 56461 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.