Frost Dates for 54011 — Ellsworth, Wisconsin

Half of springs at Ellsworth 1E, WI see their last 32°F night by May 13; only one in ten is past it by April 29, and one in ten still has one after May 27. Planting tender crops after May 19 leaves a 30% risk of a frost on them, after May 22 20%, and after May 27 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 September 29 in half of years, as early as September 15 one year in ten, and holds off past October 11 one year in ten. A hard freeze of 28°F follows 9 days later, around October 8; in spring the one-in-ten date for 28°F is May 17, 10 days before the 32°F one. The freeze-free season lasts 139 days in a typical year, shorter than at 86% of the 182 Wisconsin stations; it reaches 159 days one year in ten and falls short of 121 one year in ten. On average 166 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 23, and return around September 20. Severe cold of 16°F or below comes every winter, usually between November 5 and April 2.

July is the warmest month at Ellsworth 1E, WI, averaging 80°F by day and 57°F at night; January is the coldest at 21°F and 2°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 85% of years.

Warmth for growing adds up to 2,109 growing degree days a year (base 50°F), fewer than at 82% of the 182 Wisconsin stations. 32% of them (678) have built up by the end of June, and July adds the most, 570. Precipitation totals 36.0 inches a year, most in June (5.3") and least in January (1.0"); May to September bring 63% of it.

The nearest other station, Red Wing Dam 3, MN, 10 miles southwest of Ellsworth and 353 feet lower, has a last frost 20 days earlier (April 23), a first frost 15 days later (October 14), a season 34 days longer.

The first measurable snow (0.1 inch or more) in Ellsworth usually arrives around November 25, and the last of the season around March 19. Those are the middle dates across the winters of 1991–2020 at Ellsworth 1E, WI, 0.9 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 55 days after the last snow.

ZIP 54011 is under a mile from Ellsworth 1E, WI, which stands at 1,030 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 54011 in zone 4b, the band where the coldest night of the year averaged -25 to -20°F (-31.7 to -28.9°C) over 1991–2020; a zone describes winter lows, not frost dates.