Frost Dates for 54646 — Necedah, Wisconsin

Half of springs at Necedah, WI see their last 32°F night by May 17; only one in ten is past it by May 2, and one in ten still has one after June 1. Planting tender crops after May 23 leaves a 30% risk of a frost on them, after May 27 20%, and after June 1 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 September 25 in half of years, as early as September 12 one year in ten, and holds off past October 8 one year in ten. A hard freeze of 28°F follows 8 days later, around October 3; in spring the one-in-ten date for 28°F is May 21, 11 days before the 32°F one. The freeze-free season lasts 131 days in a typical year, shorter than at 93% of the 182 Wisconsin stations; it reaches 152 days one year in ten and falls short of 109 one year in ten. On average 164 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 12 days longer, to about May 29, and return around September 16. Severe cold of 16°F or below comes every winter, usually between November 5 and April 5.

July is the warmest month at Necedah, WI, averaging 84°F by day and 58°F at night; January is the coldest at 26°F and 6°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 11% of years.

Warmth for growing adds up to 2,459 growing degree days a year (base 50°F), more than at 54% of the 182 Wisconsin stations. 33% of them (819) have built up by the end of June, and July adds the most, 637. Precipitation totals 34.1 inches a year, most in June (5.1") and least in February (1.0"); May to September bring 61% of it.

The nearest other station, Necedah 5 WNW, WI, 5 miles west of Necedah, has a last frost 16 days earlier (May 1), a first frost 8 days later (October 3), a season 26 days longer.

The first measurable snow (0.1 inch or more) in Necedah usually arrives around November 28, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Necedah, WI, 2.2 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 42 days after the last snow.

ZIP 54646 is 2 miles from Necedah, WI, which stands at 922 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 54646 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.