Viborg climate

Viborg Frost Dates and Growing Season

NOAA 1991-2020 normals for Centerville 6 Se, 20.2 km from Viborg, elevation 1276 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Centerville 6 Se. 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 2 and the first fall freeze around October 1, a growing season of about 151 days.

Median at 36°F
last May 13, first September 22
Median at 32°F
last May 2, first October 1
Median at 28°F
last April 24, first October 11

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 25May 20May 17May 15May 13May 10May 7May 4May 1
32°FMay 15May 10May 7May 4May 2Apr 30Apr 27Apr 24Apr 19
28°FMay 6May 2Apr 30Apr 27Apr 24Apr 22Apr 18Apr 15Apr 9
24°FApr 30Apr 25Apr 22Apr 19Apr 16Apr 12Apr 9Apr 5Apr 1
20°FApr 21Apr 16Apr 12Apr 9Apr 6Apr 4Apr 1Mar 27Mar 20
16°FApr 15Apr 9Apr 5Apr 2Mar 31Mar 26Mar 22Mar 17Mar 12

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 9Sep 13Sep 17Sep 20Sep 22Sep 25Sep 29Oct 1Oct 5
32°FSep 17Sep 22Sep 26Sep 29Oct 1Oct 3Oct 6Oct 10Oct 14
28°FSep 27Oct 1Oct 4Oct 7Oct 11Oct 14Oct 17Oct 20Oct 25
24°FOct 3Oct 10Oct 15Oct 19Oct 21Oct 24Oct 27Oct 30Nov 3
20°FOct 17Oct 22Oct 25Oct 28Oct 30Nov 1Nov 4Nov 7Nov 11
16°FOct 26Oct 30Nov 2Nov 4Nov 7Nov 9Nov 12Nov 16Nov 22

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°F151145140136133129124120114
32°F169162158154151147143138132
28°F189182177174169165160155148
24°F208202197192187182178173165
20°F228221215211206202196191184
16°F245237232227223218214208199

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
7,492
Cooling degree days, base 65°F
745
Growing degree days, base 40°F
4,805
Growing degree days, base 45°F
3,758
Growing degree days, base 50°F
2,822
Growing degree days, base 55°F
2,002
Growing degree days, base 60°F
1,310

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,49200
February1,21901
March965116
April567478
May24544292
June39166578
July9259714
August20190635
September15075385
October5097111
November933012
December1,34400

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 20.2 km from Viborg. 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 USC00391579 (Centerville 6 Se). Public domain.