Frost Dates for 54024 — Saint Croix Falls, Wisconsin

Half of springs at St Croix Falls, WI see their last 32°F night by May 4; only one in ten is past it by April 20, and one in ten still has one after May 18. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 14 20%, and after May 18 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 58% of the 182 Wisconsin 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 24 one year in ten, and holds off past October 23 one year in ten. A hard freeze of 28°F follows 12 days later, around October 20; in spring the one-in-ten date for 28°F is May 8, 10 days before the 32°F one. The freeze-free season lasts 156 days in a typical year, longer than at 50% of the 182 Wisconsin stations; it reaches 175 days one year in ten and falls short of 135 one year in ten. On average 169 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 14, and return around September 29. Severe cold of 16°F or below comes every winter, usually between November 15 and March 30.

July is the warmest month at St Croix Falls, WI, averaging 82°F by day and 61°F at night; January is the coldest at 23°F and 3°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 62% of years.

Warmth for growing adds up to 2,525 growing degree days a year (base 50°F), more than at 62% of the 182 Wisconsin stations. 32% of them (817) have built up by the end of June, and July adds the most, 660. Precipitation totals 30.5 inches a year, most in July (4.2") and least in January (0.6"); May to September bring 65% of it.

The nearest other station, Wild Rvr Sp, MN, 7 miles northwest of Saint Croix Falls, has a last frost 15 days later (May 19), a first frost 13 days earlier (September 25), a season 28 days shorter.

The first measurable snow (0.1 inch or more) in Saint Croix Falls usually arrives around November 19, and the last of the season around March 27. Those are the middle dates across the winters of 1991–2020 at St Croix Falls, WI, 4.2 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 38 days after the last snow.

ZIP 54024 is 4 miles from St Croix Falls, WI, which stands at 750 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 54020 (Osceola). The 2023 USDA Plant Hardiness Zone Map lists ZIP 54024 in zone 4a, the band where the coldest night of the year averaged -30 to -25°F (-34.4 to -31.7°C) over 1991–2020; a zone describes winter lows, not frost dates.