Madison climate

Madison Frost Dates and Growing Season

NOAA 1991-2020 normals for Madison, 0.4 km from Madison, elevation 1580 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Madison. 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 30 and the first fall freeze around October 6, a growing season of about 160 days.

Median at 36°F
last May 8, first September 28
Median at 32°F
last April 30, first October 6
Median at 28°F
last April 19, first October 17

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 20May 16May 13May 10May 8May 6May 3Apr 30Apr 26
32°FMay 12May 7May 5May 2Apr 30Apr 28Apr 24Apr 20Apr 15
28°FMay 3Apr 29Apr 25Apr 22Apr 19Apr 16Apr 13Apr 9Apr 6
24°FApr 23Apr 19Apr 15Apr 12Apr 9Apr 6Apr 3Apr 1Mar 27
20°FApr 16Apr 10Apr 6Apr 3Apr 1Mar 29Mar 25Mar 21Mar 16
16°FApr 6Apr 1Mar 29Mar 26Mar 22Mar 19Mar 16Mar 13Mar 7

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 16Sep 20Sep 23Sep 26Sep 28Oct 1Oct 3Oct 6Oct 11
32°FSep 23Sep 28Oct 1Oct 3Oct 6Oct 9Oct 12Oct 15Oct 20
28°FOct 1Oct 7Oct 11Oct 14Oct 17Oct 20Oct 23Oct 25Oct 29
24°FOct 14Oct 19Oct 21Oct 24Oct 26Oct 29Nov 1Nov 3Nov 7
20°FOct 22Oct 27Oct 30Nov 1Nov 3Nov 6Nov 9Nov 13Nov 18
16°FOct 29Nov 2Nov 5Nov 9Nov 12Nov 15Nov 18Nov 22Nov 27

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°F160153148145142139135131126
32°F180173168164160156152147141
28°F200193189184180175171166160
24°F219213208204201197192187181
20°F238231226221216212208203195
16°F256248243238233229225219212

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
6,810
Cooling degree days, base 65°F
836
Growing degree days, base 40°F
5,092
Growing degree days, base 45°F
3,991
Growing degree days, base 50°F
3,012
Growing degree days, base 55°F
2,161
Growing degree days, base 60°F
1,431

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,35900
February1,10701
March890016
April514489
May21248318
June33189606
July6279738
August12224677
September12284418
October4568132
November855017
December1,24400

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 0.4 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 USC00255080 (Madison). Public domain.