Frost Dates for 54730 — Colfax, Wisconsin

Half of springs at Bloomer, WI see their last 32°F night by May 5; only one in ten is past it by April 23, and one in ten still has one after May 19. Planting tender crops after May 11 leaves a 30% risk of a frost on them, after May 14 20%, and after May 19 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 3 in half of years, as early as September 20 one year in ten, and holds off past October 17 one year in ten. A hard freeze of 28°F follows 12 days later, around October 15; in spring the one-in-ten date for 28°F is May 8, 11 days before the 32°F one. The freeze-free season lasts 151 days in a typical year, shorter than at 62% of the 182 Wisconsin stations; it reaches 168 days one year in ten and falls short of 132 one year in ten. On average 170 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 16, and return around September 25. Severe cold of 16°F or below comes every winter, usually between November 15 and March 30.

July is the warmest month at Bloomer, WI, averaging 81°F by day and 60°F at night; January is the coldest at 21°F and 3°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 72% of years.

Warmth for growing adds up to 2,357 growing degree days a year (base 50°F), fewer than at 60% of the 182 Wisconsin stations. 33% of them (785) have built up by the end of June, and July adds the most, 635. Precipitation totals 31.7 inches a year, most in June (4.5") and least in February (0.9"); May to September bring 62% of it.

The nearest other station, Menomonie, WI, 14 miles southwest of Colfax and 210 feet lower, has a last frost 4 days later (May 9), a first frost 2 days earlier (October 1), a season 8 days shorter.

The first measurable snow (0.1 inch or more) in Colfax usually arrives around November 24, and the last of the season around March 25. Those are the middle dates across the winters of 1991–2020 at Cedar Falls Hydro Plt, WI, 9.4 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 41 days after the last snow.

ZIP 54730 is 13 miles from Bloomer, WI, which stands at 990 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 54724 (Bloomer). The 2023 USDA Plant Hardiness Zone Map lists ZIP 54730 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.