Eau Claire climate

Eau Claire Frost Dates and Growing Season

NOAA 1991-2020 normals for Eau Claire 4 Ne, 5.8 km from Eau Claire, elevation 840 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Eau Claire 4 Ne. 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 April 22 and the first fall freeze around October 30, a growing season of about 189 days.

Median at 36°F
last May 1, first October 17
Median at 32°F
last April 22, first October 30
Median at 28°F
last April 9, first November 9

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 20May 13May 9May 5May 1Apr 30Apr 27Apr 23Apr 18
32°FMay 7May 1Apr 28Apr 25Apr 22Apr 19Apr 15Apr 12Apr 6
28°FApr 24Apr 19Apr 16Apr 13Apr 9Apr 6Apr 3Mar 31Mar 27
24°FApr 14Apr 8Apr 4Apr 1Mar 30Mar 27Mar 24Mar 20Mar 14
20°FApr 3Mar 30Mar 26Mar 23Mar 20Mar 17Mar 14Mar 10Mar 3
16°FMar 26Mar 21Mar 17Mar 14Mar 11Mar 8Mar 4Feb 28Feb 21

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°FOct 3Oct 7Oct 11Oct 14Oct 17Oct 20Oct 23Oct 26Nov 1
32°FOct 15Oct 20Oct 23Oct 27Oct 30Nov 1Nov 3Nov 6Nov 12
28°FOct 27Nov 1Nov 3Nov 6Nov 9Nov 12Nov 15Nov 19Nov 25
24°FNov 3Nov 9Nov 13Nov 16Nov 20Nov 23Nov 27Dec 1Dec 6
20°FNov 12Nov 18Nov 22Nov 27Nov 30Dec 3Dec 7Dec 12Dec 18
16°FNov 22Nov 28Dec 2Dec 6Dec 9Dec 13Dec 18Dec 23Dec 29

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°F185179175170166163158152146
32°F209203198194189185180176167
28°F233226221217213209205199192
24°F256249243238233229225219213
20°F279270264259254249244238230
16°F297290283279274269264257247

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
5,815
Cooling degree days, base 65°F
964
Growing degree days, base 40°F
5,578
Growing degree days, base 45°F
4,401
Growing degree days, base 50°F
3,349
Growing degree days, base 55°F
2,421
Growing degree days, base 60°F
1,622

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,19301
February1,00402
March817337
April4499125
May17669368
June28204625
July2297759
August6250710
September74113490
October34019196
November693032
December1,03404

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 5.8 km from Eau Claire. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00202445 (Eau Claire 4 Ne). Public domain.