Frost Dates for 54440 — Hatley, Wisconsin

Half of springs at Rosholt 9 NNE, WI see their last 32°F night by May 6; only one in ten is past it by April 24, and one in ten still has one after May 21. Planting tender crops after May 12 leaves a 30% risk of a frost on them, after May 16 20%, and after May 21 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 30% of the 182 Wisconsin stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 5 in half of years, as early as September 22 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 12 days later, around October 17; in spring the one-in-ten date for 28°F is May 10, 11 days before the 32°F one. The freeze-free season lasts 150 days in a typical year, shorter than at 64% of the 182 Wisconsin stations; it reaches 169 days one year in ten and falls short of 130 one year in ten. On average 178 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 19, and return around September 26. Severe cold of 16°F or below comes every winter, usually between November 18 and March 29.

July is the warmest month at Rosholt 9 NNE, WI, averaging 81°F by day and 58°F at night; January is the coldest at 24°F and 7°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 70% of years.

Warmth for growing adds up to 2,320 growing degree days a year (base 50°F), fewer than at 63% of the 182 Wisconsin stations. 32% of them (751) have built up by the end of June, and July adds the most, 608. Precipitation totals 34.0 inches a year, most in June (4.5") and least in February (1.1"); May to September bring 59% of it.

The nearest other station, Wausau Dwtn Airport, WI, 14 miles northwest of Hatley, has the same 50% last-frost date, a first frost 1 day earlier (October 4).

The first measurable snow (0.1 inch or more) in Hatley usually arrives around November 6, and the last of the season around April 12. Those are the middle dates across the winters of 1991–2020 at Rosholt 9 NNE, WI, 8.4 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 24 days after the last snow.

ZIP 54440 is 8 miles from Rosholt 9 NNE, WI, which stands at 1,183 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 54945 (Iola). The 2023 USDA Plant Hardiness Zone Map lists ZIP 54440 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.