Chippewa Falls climate

Chippewa Falls Frost Dates and Growing Season

NOAA 1991-2020 normals for Eau Claire Rgnl AP, 10.8 km from Chippewa Falls, elevation 885 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Eau Claire Rgnl AP. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around May 8 and the first fall freeze around October 4, a growing season of about 149 days.

Median at 36°F
last May 17, first September 25
Median at 32°F
last May 8, first October 4
Median at 28°F
last April 27, first October 15

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FMay 31May 26May 23May 20May 17May 15May 13May 10May 5
32°FMay 21May 17May 13May 11May 8May 5May 2Apr 30Apr 24
28°FMay 12May 6May 2Apr 30Apr 27Apr 24Apr 21Apr 18Apr 13
24°FMay 1Apr 26Apr 23Apr 20Apr 17Apr 13Apr 10Apr 6Apr 3
20°FApr 21Apr 16Apr 12Apr 8Apr 5Apr 3Apr 1Mar 30Mar 24
16°FApr 13Apr 6Apr 3Apr 1Mar 31Mar 27Mar 23Mar 20Mar 15

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 10Sep 16Sep 20Sep 22Sep 25Sep 27Oct 1Oct 3Oct 8
32°FSep 20Sep 25Sep 29Oct 1Oct 4Oct 7Oct 10Oct 12Oct 17
28°FOct 1Oct 6Oct 9Oct 12Oct 15Oct 18Oct 20Oct 23Oct 27
24°FOct 12Oct 17Oct 20Oct 23Oct 26Oct 28Oct 31Nov 3Nov 8
20°FOct 24Oct 29Nov 1Nov 2Nov 5Nov 8Nov 11Nov 14Nov 18
16°FNov 1Nov 5Nov 8Nov 11Nov 14Nov 17Nov 19Nov 23Nov 27

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F147141136133129126122117110
32°F166160156152149145140135128
28°F188180176172169165161156151
24°F211204199196191187183178171
20°F232224219215211207203198192
16°F249242236233228224220216210

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
7,923
Cooling degree days, base 65°F
567
Growing degree days, base 40°F
4,415
Growing degree days, base 45°F
3,406
Growing degree days, base 50°F
2,513
Growing degree days, base 55°F
1,736
Growing degree days, base 60°F
1,081

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,56200
February1,29500
March1,047011
April607257
May26628255
June57120513
July12207660
August27153590
September17953337
October548482
November95007
December1,37500

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 10.8 km from Chippewa Falls. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00014991 (Eau Claire Rgnl AP). Public domain.