Madison climate

Madison Frost Dates and Growing Season

NOAA 1991-2020 normals for Tamworth 4, 10.2 km from Madison, elevation 541 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Tamworth 4. 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 16 and the first fall freeze around September 26, a growing season of about 129 days.

Median at 36°F
last May 29, first September 14
Median at 32°F
last May 16, first September 26
Median at 28°F
last May 4, first October 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°FJun 11Jun 6Jun 3Jun 1May 29May 26May 23May 20May 15
32°FMay 30May 26May 23May 20May 16May 14May 11May 7May 3
28°FMay 19May 14May 10May 7May 4May 2Apr 30Apr 27Apr 24
24°FMay 4Apr 30Apr 26Apr 23Apr 21Apr 18Apr 15Apr 11Apr 8
20°FApr 22Apr 16Apr 12Apr 9Apr 8Apr 6Apr 4Apr 2Mar 30
16°FApr 9Apr 6Apr 3Apr 2Mar 31Mar 30Mar 26Mar 22Mar 17

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 1Sep 5Sep 8Sep 11Sep 14Sep 17Sep 20Sep 24Sep 28
32°FSep 10Sep 15Sep 19Sep 23Sep 26Sep 28Oct 1Oct 3Oct 7
28°FSep 21Sep 26Oct 1Oct 2Oct 4Oct 7Oct 10Oct 14Oct 20
24°FOct 1Oct 6Oct 11Oct 14Oct 18Oct 21Oct 26Nov 1Nov 4
20°FOct 17Oct 23Oct 28Oct 31Nov 2Nov 5Nov 8Nov 13Nov 17
16°FNov 1Nov 6Nov 11Nov 14Nov 17Nov 19Nov 22Nov 25Dec 1

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°F1251191141101061031009691
32°F148141137132129125122117110
28°F170164159155151147144138131
24°F201193188183178174169164157
20°F226220215211207203199193184
16°F248241237233229226222217211

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
8,211
Cooling degree days, base 65°F
214
Growing degree days, base 40°F
3,505
Growing degree days, base 45°F
2,567
Growing degree days, base 50°F
1,758
Growing degree days, base 55°F
1,085
Growing degree days, base 60°F
556

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,44400
February1,25600
March1,12502
April721124
May3817146
June14339350
July4390511
August7061456
September26115227
October614040
November90504
December1,24800

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 10.2 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 USC00278614 (Tamworth 4). Public domain.