Frost Dates for 55009 — Cannon Falls, Minnesota

Half of springs at Red Wing Dam 3, MN see their last 32°F night by April 23; only one in ten is past it by April 8, and one in ten still has one after May 7. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 2 20%, and after May 7 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 October 14 in half of years, as early as September 28 one year in ten, and holds off past October 28 one year in ten. A hard freeze of 28°F follows 11 days later, around October 25; in spring the one-in-ten date for 28°F is April 28, 9 days before the 32°F one. The freeze-free season lasts 173 days in a typical year, longer than at 94% of the 142 Minnesota stations; it reaches 192 days one year in ten and falls short of 152 one year in ten. On average 154 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 4, and return around October 4. Severe cold of 16°F or below comes every winter, usually between November 20 and March 22.

July is the warmest month at Red Wing Dam 3, MN, averaging 82°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 24% of years.

Warmth for growing adds up to 2,702 growing degree days a year (base 50°F), more than at 82% of the 142 Minnesota stations. 33% of them (893) have built up by the end of June, and July adds the most, 694. Precipitation totals 32.6 inches a year, most in June (5.1") and least in January (0.8"); May to September bring 65% of it.

The nearest other station, Zumbrota, MN, 18 miles southeast of Cannon Falls and 293 feet higher, has a last frost 16 days later (May 9), a first frost 14 days earlier (September 30), a season 29 days shorter.

The first measurable snow (0.1 inch or more) in Cannon Falls usually arrives around November 30, and the last of the season around March 18. Those are the middle dates across the winters of 1991–2020 at Red Wing Dam 3, MN, 16.1 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 36 days after the last snow.

ZIP 55009 is 16 miles from Red Wing Dam 3, MN, which stands at 677 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 55066 (Red Wing). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55009 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.