Frost Dates for 55317 — Chanhassen, Minnesota

Half of springs at Chanhassen Wsfo, MN see their last 32°F night by April 30; only one in ten is past it by April 15, and one in ten still has one after May 15. Planting tender crops after May 6 leaves a 30% risk of a frost on them, after May 9 20%, and after May 15 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 9 in half of years, as early as September 25 one year in ten, and holds off past October 21 one year in ten. A hard freeze of 28°F follows 10 days later, around October 19; in spring the one-in-ten date for 28°F is May 4, 11 days before the 32°F one. The freeze-free season lasts 160 days in a typical year, longer than at 77% of the 142 Minnesota stations; it reaches 178 days one year in ten and falls short of 140 one year in ten. On average 156 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 9 days longer, to about May 9, and return around September 30. Severe cold of 16°F or below comes every winter, usually between November 14 and March 26.

July is the warmest month at Chanhassen Wsfo, MN, averaging 81°F by day and 62°F at night; January is the coldest at 22°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 47% of years.

Warmth for growing adds up to 2,566 growing degree days a year (base 50°F), more than at 67% of the 142 Minnesota stations. 33% of them (848) have built up by the end of June, and July adds the most, 674. Precipitation totals 33.0 inches a year, most in August (4.8") and least in January (0.9"); May to September bring 63% of it.

The nearest other station, Mpls Flying Cloud Airport, MN, 4 miles southeast of Chanhassen, has a last frost 7 days earlier (April 23), a first frost 5 days later (October 14), a season 12 days longer.

The first measurable snow (0.1 inch or more) in Chanhassen usually arrives around November 8, and the last of the season around April 10. Those are the middle dates across the winters of 1991–2020 at Chanhassen Wsfo, MN, 1.5 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 20 days after the last snow.

ZIP 55317 is 2 miles from Chanhassen Wsfo, MN, which stands at 946 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 55317 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.