Frost Dates for 55405 — Minneapolis, Minnesota

Half of springs at Lower St Anthony Falls, MN see their last 32°F night by April 23; only one in ten is past it by April 10, 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 16 in half of years, as early as October 2 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 11 days later, around October 27; in spring the one-in-ten date for 28°F is April 27, 10 days before the 32°F one. The freeze-free season lasts 175 days in a typical year, longer than at 95% of the 142 Minnesota stations; it reaches 192 days one year in ten and falls short of 155 one year in ten. On average 147 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 5. Severe cold of 16°F or below comes every winter, usually between November 22 and March 22.

July is the warmest month at Lower St Anthony Falls, MN, averaging 83°F by day and 64°F at night; January is the coldest at 22°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 September 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 2,799 growing degree days a year (base 50°F), more than at 90% of the 142 Minnesota stations. 33% of them (929) have built up by the end of June, and July adds the most, 731. Precipitation totals 34.5 inches a year, most in June (4.8") and least in February (0.9"); May to September bring 63% of it.

The nearest other station, New Hope, MN, 5 miles northwest of Minneapolis and 156 feet higher, has a last frost 6 days later (April 29), a first frost 4 days earlier (October 12), a season 12 days shorter.

The first measurable snow (0.1 inch or more) in Minneapolis 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, 4.6 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 12 days after the last snow.

ZIP 55405 is 3 miles from Lower St Anthony Falls, MN, which stands at 754 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 13 other ZIP codes share the station; its figures are presented in full for 55407 (Minneapolis). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55405 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.