Dodge County climate

Dodge County Frost Dates and Growing Season

NOAA 1991-2020 normals for Byron 4NORTH, 19.3 km from Dodge County, elevation 1041 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Byron 4NORTH. 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 12 and the first fall freeze around September 28, a growing season of about 139 days.

Median at 36°F
last May 22, first September 19
Median at 32°F
last May 12, first September 28
Median at 28°F
last May 2, first October 5

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 4May 31May 28May 25May 22May 20May 17May 14May 8
32°FMay 25May 21May 18May 15May 12May 9May 7May 3Apr 29
28°FMay 15May 11May 7May 4May 2Apr 30Apr 27Apr 23Apr 18
24°FMay 6May 1Apr 28Apr 25Apr 22Apr 19Apr 15Apr 11Apr 6
20°FApr 26Apr 21Apr 17Apr 14Apr 11Apr 8Apr 5Apr 2Mar 30
16°FApr 18Apr 10Apr 6Apr 4Apr 1Mar 30Mar 27Mar 23Mar 16

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 5Sep 11Sep 14Sep 17Sep 19Sep 22Sep 25Sep 28Oct 2
32°FSep 14Sep 19Sep 22Sep 25Sep 28Oct 1Oct 3Oct 5Oct 10
28°FSep 22Sep 27Oct 1Oct 3Oct 5Oct 8Oct 11Oct 14Oct 18
24°FOct 2Oct 6Oct 9Oct 12Oct 14Oct 17Oct 20Oct 23Oct 28
20°FOct 11Oct 16Oct 20Oct 23Oct 26Oct 29Nov 1Nov 4Nov 9
16°FOct 22Oct 27Oct 31Nov 2Nov 4Nov 8Nov 11Nov 17Nov 21

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°F138132128124120116112107101
32°F156150147143139135131125118
28°F175169164160156152149144137
24°F197190184180176173169163156
20°F218211206202197194190184177
16°F238231224220216212208203196

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
8,328
Cooling degree days, base 65°F
442
Growing degree days, base 40°F
4,112
Growing degree days, base 45°F
3,134
Growing degree days, base 50°F
2,272
Growing degree days, base 55°F
1,531
Growing degree days, base 60°F
915

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,61000
February1,35100
March1,087010
April653141
May30921218
June66101486
July20164609
August43111533
September20941301
October597369
November98005
December1,40400

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 19.3 km from Dodge County. 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 USC00211174 (Byron 4NORTH). Public domain.