Frost Dates for 55343 — Minnetonka, Minnesota

Half of springs at New Hope, MN see their last 32°F night by April 29; only one in ten is past it by April 15, and one in ten still has one after May 12. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 7 20%, and after May 12 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 12 in half of years, as early as September 29 one year in ten, and holds off past October 25 one year in ten. A hard freeze of 28°F follows 10 days later, around October 22; in spring the one-in-ten date for 28°F is May 1, 11 days before the 32°F one. The freeze-free season lasts 163 days in a typical year, longer than at 84% of the 142 Minnesota stations; it reaches 182 days one year in ten and falls short of 144 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 8, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 16 and March 26.

July is the warmest month at New Hope, MN, averaging 82°F by day and 63°F at night; January is the coldest at 24°F and 7°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 41% of years.

Warmth for growing adds up to 2,711 growing degree days a year (base 50°F), more than at 85% of the 142 Minnesota stations. 33% of them (904) have built up by the end of June, and July adds the most, 704. Precipitation totals 34.8 inches a year, most in June (4.6") and least in January (1.0"); May to September bring 61% of it.

The nearest other station, Mpls Flying Cloud Airport, MN, 7 miles southwest of Minnetonka, has a last frost 6 days earlier (April 23), a first frost 2 days later (October 14), a season 9 days longer.

The first measurable snow (0.1 inch or more) in Minnetonka usually arrives around November 7, and the last of the season around April 11. Those are the middle dates across the winters of 1991–2020 at New Hope, MN, 6.3 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 18 days after the last snow.

ZIP 55343 is 6 miles from New Hope, MN, which stands at 910 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 11 other ZIP codes share the station; its figures are presented in full for 55416 (St Louis Park). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55343 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.