Frost Dates for 54235 — Sturgeon Bay, Wisconsin

Half of springs at Sturgeon Bay Exp Farm, WI see their last 32°F night by May 8; only one in ten is past it by April 25, and one in ten still has one after May 21. Planting tender crops after May 13 leaves a 30% risk of a frost on them, after May 17 20%, and after May 21 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 84% of the 182 Wisconsin stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 13 in half of years, as early as September 28 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 15 days later, around October 28; in spring the one-in-ten date for 28°F is May 9, 12 days before the 32°F one. The freeze-free season lasts 157 days in a typical year, longer than at 53% of the 182 Wisconsin stations; it reaches 177 days one year in ten and falls short of 137 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 13 days longer, to about May 21, and return around October 2. Severe cold of 16°F or below comes every winter, usually between November 28 and March 25.

July is the warmest month at Sturgeon Bay Exp Farm, WI, averaging 78°F by day and 59°F at night; January is the coldest at 25°F and 10°F. A freezing night is all but certain in every month from November 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 76% of years.

Warmth for growing adds up to 2,030 growing degree days a year (base 50°F), fewer than at 85% of the 182 Wisconsin stations. 27% of them (540) have built up by the end of June, and July adds the most, 570. Precipitation totals 32.8 inches a year, most in June (4.1") and least in February (1.3"); May to September bring 53% of it.

The nearest other station, Forestville-4E, WI, 10 miles south of Sturgeon Bay, has a last frost 2 days earlier (May 6), a first frost 4 days later (October 17), a season 6 days longer.

The first measurable snow (0.1 inch or more) in Sturgeon Bay usually arrives around November 25, and the last of the season around April 9. Those are the middle dates across the winters of 1991–2020 at Sturgeon Bay Exp Farm, WI, 3.3 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 29 days after the last snow.

ZIP 54235 is 3 miles from Sturgeon Bay Exp Farm, WI, which stands at 699 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 54235 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.