Barneveld climate

Barneveld Frost Dates and Growing Season

NOAA 1991-2020 normals for Mazomanie Wwtp, 18.2 km from Barneveld, elevation 764 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mazomanie Wwtp. 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 7 and the first fall freeze around October 1, a growing season of about 148 days.

Median at 36°F
last May 18, first September 23
Median at 32°F
last May 7, first October 1
Median at 28°F
last April 27, first October 12

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°FJun 1May 28May 24May 21May 18May 14May 11May 6Apr 30
32°FMay 22May 17May 13May 10May 7May 4Apr 30Apr 27Apr 22
28°FMay 13May 7May 3Apr 30Apr 27Apr 24Apr 20Apr 16Apr 12
24°FMay 3Apr 28Apr 23Apr 20Apr 16Apr 13Apr 10Apr 6Apr 2
20°FApr 22Apr 15Apr 10Apr 7Apr 5Apr 2Mar 31Mar 26Mar 20
16°FApr 9Apr 4Apr 1Mar 30Mar 26Mar 23Mar 19Mar 15Mar 10

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 11Sep 15Sep 18Sep 21Sep 23Sep 26Sep 29Oct 1Oct 6
32°FSep 18Sep 23Sep 26Sep 29Oct 1Oct 4Oct 7Oct 10Oct 16
28°FSep 26Oct 1Oct 4Oct 8Oct 12Oct 15Oct 18Oct 22Oct 29
24°FOct 7Oct 14Oct 18Oct 21Oct 24Oct 27Oct 30Nov 3Nov 8
20°FOct 21Oct 27Oct 31Nov 2Nov 5Nov 8Nov 12Nov 16Nov 20
16°FNov 2Nov 7Nov 11Nov 15Nov 17Nov 20Nov 23Nov 27Dec 1

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°F149141136132128125121115107
32°F168160155151148144140134128
28°F188182176172167163157153146
24°F212204199194190185180174166
20°F233227221217212208204199192
16°F256249244240235231227222214

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
7,497
Cooling degree days, base 65°F
528
Growing degree days, base 40°F
4,427
Growing degree days, base 45°F
3,391
Growing degree days, base 50°F
2,486
Growing degree days, base 55°F
1,701
Growing degree days, base 60°F
1,042

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,47100
February1,21900
March997215
April600358
May27642266
June59111503
July19172618
August27146584
September17848332
October510699
November864011
December1,27900

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 18.2 km from Barneveld. 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 USC00475189 (Mazomanie Wwtp). Public domain.