Frost Dates for 54937 — Fond Du Lac, Wisconsin

Half of springs at Fond Du Lac Co Airport, WI see their last 32°F night by May 1; only one in ten is past it by April 17, and one in ten still has one after May 17. Planting tender crops after May 8 leaves a 30% risk of a frost on them, after May 12 20%, and after May 17 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 70% 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 27 one year in ten, and holds off past October 25 one year in ten. A hard freeze of 28°F follows 13 days later, around October 23; in spring the one-in-ten date for 28°F is May 6, 11 days before the 32°F one. The freeze-free season lasts 160 days in a typical year, longer than at 60% of the 182 Wisconsin stations; it reaches 180 days one year in ten and falls short of 140 one year in ten. On average 143 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 12, and return around September 30. Severe cold of 16°F or below comes every winter, usually between November 23 and March 21.

July is the warmest month at Fond Du Lac Co Airport, WI, averaging 82°F by day and 61°F at night; January is the coldest at 27°F and 11°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 52% of years.

Warmth for growing adds up to 2,600 growing degree days a year (base 50°F), more than at 71% of the 182 Wisconsin stations. 33% of them (851) have built up by the end of June, and July adds the most, 662. Precipitation totals 28.3 inches a year, most in June (4.1") and least in January (0.7"); May to September bring 61% of it.

The nearest other station, Fond Du Lac 2 SW, WI, 2 miles southeast of Fond Du Lac, has a last frost 4 days earlier (April 27), a first frost 9 days later (October 19), a season 14 days longer.

The first measurable snow (0.1 inch or more) in Fond Du Lac usually arrives around November 22, and the last of the season around April 3. Those are the middle dates across the winters of 1991–2020 at Fond Du Lac Wwtp, WI, 1.8 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 28 days after the last snow.

ZIP 54937 is 1 mile from Fond Du Lac Co Airport, WI, which stands at 809 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 54937 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.