Madison climate

Madison Frost Dates and Growing Season

NOAA 1991-2020 normals for Madison 3NNW, 4.6 km from Madison, elevation 689 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Madison 3NNW. 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 16 and the first fall freeze around October 27, a growing season of about 192 days.

Median at 36°F
last April 29, first October 18
Median at 32°F
last April 16, first October 27
Median at 28°F
last April 3, first November 4

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 13May 8May 4May 1Apr 29Apr 25Apr 23Apr 19Apr 15
32°FMay 2Apr 25Apr 22Apr 19Apr 16Apr 13Apr 10Apr 6Apr 2
28°FApr 18Apr 13Apr 9Apr 6Apr 3Mar 31Mar 29Mar 24Mar 18
24°FApr 6Apr 1Mar 30Mar 26Mar 23Mar 19Mar 15Mar 10Mar 3
20°FMar 28Mar 22Mar 17Mar 14Mar 9Mar 4Feb 28Feb 23Feb 16
16°FMar 17Mar 10Mar 4Feb 28Feb 22Feb 17Feb 11Feb 5Jan 31

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 6Oct 10Oct 13Oct 15Oct 18Oct 21Oct 23Oct 26Oct 30
32°FOct 13Oct 19Oct 22Oct 25Oct 27Oct 30Nov 1Nov 3Nov 6
28°FOct 23Oct 28Nov 1Nov 2Nov 4Nov 6Nov 9Nov 12Nov 18
24°FNov 1Nov 5Nov 9Nov 11Nov 14Nov 18Nov 22Nov 28Dec 3
20°FNov 11Nov 16Nov 20Nov 25Nov 30Dec 2Dec 6Dec 13Dec 22
16°FNov 23Dec 1Dec 5Dec 12Dec 17Dec 23Dec 28Jan 1Jan 9

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°F190185181177173169164160154
32°F209203199195192188185180172
28°F233227222218214210205201195
24°F261253247242237232228223217
20°F293283277271265259254247238
16°F324314307301295290282274265

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
4,426
Cooling degree days, base 65°F
1,216
Growing degree days, base 40°F
6,575
Growing degree days, base 45°F
5,203
Growing degree days, base 50°F
3,983
Growing degree days, base 55°F
2,916
Growing degree days, base 60°F
1,995

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January939014
February762016
March612373
April29421230
May104102467
June11239678
July0350815
August1316780
September39157569
October26626256
November571165
December826021

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 4.6 km from Madison. 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 USC00465563 (Madison 3NNW). Public domain.