Madison climate

Madison Frost Dates and Growing Season

NOAA 1991-2020 normals for Wynne, 27.7 km from Madison, elevation 260 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wynne. 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 March 23 and the first fall freeze around November 7, a growing season of about 231 days.

Median at 36°F
last April 4, first October 28
Median at 32°F
last March 23, first November 7
Median at 28°F
last March 9, first November 20

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

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 15Oct 20Oct 23Oct 25Oct 28Oct 31Nov 2Nov 5Nov 12
32°FOct 24Oct 30Nov 1Nov 4Nov 7Nov 10Nov 15Nov 20Nov 27
28°FNov 2Nov 6Nov 11Nov 16Nov 20Nov 24Nov 30Dec 3Dec 12
24°FNov 10Nov 20Nov 25Dec 1Dec 5Dec 11Dec 19Dec 26Jan 4
20°FNov 27Dec 5Dec 14Dec 23Dec 29Jan 3Jan 8Jan 13Jan 25
16°FDec 14Dec 26Jan 1Jan 5Jan 10Jan 15Jan 20Jan 28Feb 5

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°F231222217212209205200195189
32°F256246240235231226221215206
28°F285275267261255249243237229
24°F319306298291284278272264253
20°F353340333325316309303293278
16°F365365361352344336331321307

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
96% of years
16°F or colder
74% 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
3,163
Cooling degree days, base 65°F
2,183
Growing degree days, base 40°F
8,441
Growing degree days, base 45°F
6,905
Growing degree days, base 50°F
5,507
Growing degree days, base 55°F
4,255
Growing degree days, base 60°F
3,143

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January766131
February588255
March40215171
April15469377
May28235671
June1441891
July0533998
August0485950
September13291727
October13498438
November40712149
December669149

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 27.7 km from Madison. 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 USC00038052 (Wynne). Public domain.