Frost Dates for 53941 — La Valle, Wisconsin

Half of springs at Reedsburg, WI see their last 32°F night by May 2; only one in ten is past it by April 18, and one in ten still has one after May 16. Planting tender crops after May 7 leaves a 30% risk of a frost on them, after May 11 20%, and after May 16 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 7 in half of years, as early as September 23 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 11 days later, around October 18; in spring the one-in-ten date for 28°F is May 5, 11 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 176 days one year in ten and falls short of 138 one year in ten. On average 154 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 13, and return around September 29. Severe cold of 16°F or below comes every winter, usually between November 20 and March 22.

July is the warmest month at Reedsburg, WI, averaging 82°F by day and 61°F at night; January is the coldest at 27°F and 8°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 54% of years.

Warmth for growing adds up to 2,595 growing degree days a year (base 50°F), more than at 71% of the 182 Wisconsin stations. 34% of them (878) have built up by the end of June, and July adds the most, 668. Precipitation totals 39.6 inches a year, most in June (5.4") and least in January (1.5"); May to September bring 59% of it.

The nearest other station, Hillsboro, WI, 11 miles northwest of La Valle, has a last frost 3 days later (May 5), a first frost 3 days earlier (October 4), a season 3 days shorter.

The first measurable snow (0.1 inch or more) in La Valle usually arrives around November 25, and the last of the season around March 23. Those are the middle dates across the winters of 1991–2020 at Reedsburg, WI, 7.8 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 40 days after the last snow.

ZIP 53941 is 8 miles from Reedsburg, WI, which stands at 926 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 53959 (Reedsburg). The 2023 USDA Plant Hardiness Zone Map lists ZIP 53941 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.