Frost Dates for 55005 — Bethel, Minnesota

Half of springs at Cedar, MN see their last 32°F night by May 1; only one in ten is past it by April 17, and one in ten still has one after May 17. Planting tender crops after May 7 leaves a 30% risk of a frost on them, after May 10 20%, and after May 17 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 77% of the 142 Minnesota stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 7 in half of years, as early as September 23 one year in ten, and holds off past October 22 one year in ten. A hard freeze of 28°F follows 12 days later, around October 19; in spring the one-in-ten date for 28°F is May 3, 14 days before the 32°F one. The freeze-free season lasts 158 days in a typical year, longer than at 72% of the 142 Minnesota stations; it reaches 178 days one year in ten and falls short of 137 one year in ten. On average 162 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 12, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 14 and March 26.

July is the warmest month at Cedar, MN, averaging 80°F by day and 62°F at night; January is the coldest at 23°F and 6°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 50% of years.

Warmth for growing adds up to 2,515 growing degree days a year (base 50°F), more than at 61% of the 142 Minnesota stations. 33% of them (840) have built up by the end of June, and July adds the most, 646. Precipitation totals 34.4 inches a year, most in July (4.8") and least in January (0.9"); May to September bring 61% of it.

The nearest other station, Andover 1N, MN, 10 miles south of Bethel, has a last frost 4 days later (May 5), a first frost 5 days earlier (October 2), a season 10 days shorter.

The first measurable snow (0.1 inch or more) in Bethel usually arrives around November 5, and the last of the season around April 14. Those are the middle dates across the winters of 1991–2020 at Cedar, MN, 5.6 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 17 days after the last snow.

ZIP 55005 is 6 miles from Cedar, MN, which stands at 907 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 55011 (East Bethel). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55005 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.