Frost Dates for 55108 — Saint Paul, Minnesota

Half of springs at U Of Mn St Paul, MN see their last 32°F night by April 28; only one in ten is past it by April 14, and one in ten still has one after May 14. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 7 20%, and after May 14 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 77% of the 142 Minnesota stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 8 in half of years, as early as September 25 one year in ten, and holds off past October 22 one year in ten. A hard freeze of 28°F follows 13 days later, around October 21; in spring the one-in-ten date for 28°F is May 1, 13 days before the 32°F one. The freeze-free season lasts 162 days in a typical year, longer than at 81% of the 142 Minnesota stations; it reaches 183 days one year in ten and falls short of 142 one year in ten. On average 152 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 7, and return around September 30. Severe cold of 16°F or below comes every winter, usually between November 15 and March 25.

July is the warmest month at U Of Mn St Paul, MN, averaging 81°F by day and 63°F at night; January is the coldest at 21°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 40% of years.

Warmth for growing adds up to 2,650 growing degree days a year (base 50°F), more than at 77% of the 142 Minnesota stations. 33% of them (880) have built up by the end of June, and July adds the most, 685. Precipitation totals 32.8 inches a year, most in June (4.6") and least in January (0.7"); May to September bring 65% of it.

The nearest other station, Lower St Anthony Falls, MN, 4 miles west of Saint Paul and 216 feet lower, has a last frost 5 days earlier (April 23), a first frost 8 days later (October 16), a season 13 days longer.

The first measurable snow (0.1 inch or more) in Saint Paul usually arrives around November 27, and the last of the season around March 24. Those are the middle dates across the winters of 1991–2020 at Vadnais Lake, 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 35 days after the last snow.

ZIP 55108 is under a mile from U Of Mn St Paul, MN, which stands at 970 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 55117 (Saint Paul). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55108 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.