Frost Dates for 55345 — Minnetonka, Minnesota

Half of springs at Mpls Flying Cloud Airport, MN see their last 32°F night by April 23; only one in ten is past it by April 9, and one in ten still has one after May 6. Planting tender crops after April 29 leaves a 30% risk of a frost on them, after May 1 20%, and after May 6 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 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 26, 10 days before the 32°F one. The freeze-free season lasts 172 days in a typical year, longer than at 93% of the 142 Minnesota stations; it reaches 191 days one year in ten and falls short of 152 one year in ten. On average 145 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 10 days longer, to about May 3, 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 Mpls Flying Cloud Airport, MN, averaging 84°F by day and 64°F at night; January is the coldest at 24°F and 8°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 22% of years.

Warmth for growing adds up to 2,932 growing degree days a year (base 50°F), more than at 95% of the 142 Minnesota stations. 34% of them (992) have built up by the end of June, and July adds the most, 739. Precipitation totals 30.8 inches a year, most in June (4.7") and least in February (0.6"); May to September bring 67% of it.

The nearest other station, Chanhassen Wsfo, MN, 6 miles southwest of Minnetonka, has a last frost 7 days later (April 30), a first frost 5 days earlier (October 9), a season 12 days shorter.

The first measurable snow (0.1 inch or more) in Minnetonka 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, 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 13 days after the last snow.

ZIP 55345 is 6 miles from Mpls Flying Cloud Airport, MN, which stands at 907 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 10 other ZIP codes share the station; its figures are presented in full for 55379 (Shakopee). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55345 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.