Frost Dates for 53585 — Sharon, Wisconsin

Half of springs at Clinton Wwtp, WI see their last 32°F night by April 30; only one in ten is past it by April 15, and one in ten still has one after May 17. Planting tender crops after May 6 leaves a 30% risk of a frost on them, after May 12 20%, and after May 17 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 90% of the 182 Wisconsin stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 10 in half of years, as early as September 26 one year in ten, and holds off past October 24 one year in ten. A hard freeze of 28°F follows 10 days later, around October 20; in spring the one-in-ten date for 28°F is May 7, 10 days before the 32°F one. The freeze-free season lasts 161 days in a typical year, longer than at 62% of the 182 Wisconsin stations; it reaches 180 days one year in ten and falls short of 141 one year in ten. On average 148 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 11, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 21 and March 17.

July is the warmest month at Clinton Wwtp, WI, averaging 82°F by day and 61°F at night; January is the coldest at 27°F and 10°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 48% of years.

Warmth for growing adds up to 2,687 growing degree days a year (base 50°F), more than at 80% of the 182 Wisconsin stations. 34% of them (912) have built up by the end of June, and July adds the most, 663. Precipitation totals 37.8 inches a year, most in June (5.5") and least in January (1.6"); May to September bring 57% of it.

The nearest other station, Delavan Wwtp, WI, 9 miles north of Sharon, has a last frost 2 days earlier (April 28), a first frost 4 days later (October 14), a season 7 days longer.

The first measurable snow (0.1 inch or more) in Sharon usually arrives around November 22, and the last of the season around March 31. Those are the middle dates across the winters of 1991–2020 at Harvard, IL, 8.6 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 30 days after the last snow.

ZIP 53585 is 8 miles from Clinton Wwtp, WI, which stands at 924 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 61065 (Poplar Grove). The 2023 USDA Plant Hardiness Zone Map lists ZIP 53585 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.