Frost Dates for 55718 — Carlton, Minnesota

Half of springs at Cloquet, MN see their last 32°F night by May 26; only one in ten is past it by May 13, and one in ten still has one after June 9. Planting tender crops after June 1 leaves a 30% risk of a frost on them, after June 4 20%, and after June 9 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 23 in half of years, as early as September 9 one year in ten, and holds off past October 4 one year in ten. A hard freeze of 28°F follows 10 days later, around October 3; in spring the one-in-ten date for 28°F is May 28, 12 days before the 32°F one. The freeze-free season lasts 118 days in a typical year, shorter than at 97% of the 142 Minnesota stations; it reaches 137 days one year in ten and falls short of 97 one year in ten. On average 191 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 12 days longer, to about June 7, and return around September 12. Severe cold of 16°F or below comes every winter, usually between November 7 and April 8.

July is the warmest month at Cloquet, MN, averaging 79°F by day and 54°F at night; January is the coldest at 18°F and 2°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 32% of years.

Warmth for growing adds up to 1,680 growing degree days a year (base 50°F), fewer than at 93% of the 142 Minnesota stations. 28% of them (462) have built up by the end of June, and July adds the most, 504. Precipitation totals 32.8 inches a year, most in June (4.8") and least in January (1.0"); May to September bring 62% of it.

The nearest other station, Duluth NWS, MN, 18 miles northeast of Carlton and 168 feet higher, has a last frost 8 days earlier (May 18), a first frost 8 days later (October 1), a season 17 days longer.

The first measurable snow (0.1 inch or more) in Carlton usually arrives around November 1, and the last of the season around April 17. Those are the middle dates across the winters of 1991–2020 at Cloquet, MN, 4.3 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 39 days after the last snow.

ZIP 55718 is 4 miles from Cloquet, MN, which stands at 1,265 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 55720 (Cloquet). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55718 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.