Madisonville climate

Madisonville Frost Dates and Growing Season

NOAA 1991-2020 normals for Tellico Plains, 17.7 km from Madisonville, elevation 910 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Tellico Plains. 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 13 and the first fall freeze around October 24, a growing season of about 193 days.

Median at 36°F
last April 25, first October 15
Median at 32°F
last April 13, first October 24
Median at 28°F
last March 31, first November 2

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 9May 4Apr 30Apr 28Apr 25Apr 21Apr 19Apr 15Apr 9
32°FApr 29Apr 24Apr 20Apr 17Apr 13Apr 9Apr 6Apr 2Mar 27
28°FApr 18Apr 10Apr 6Apr 3Mar 31Mar 27Mar 22Mar 16Mar 8
24°FApr 3Mar 29Mar 24Mar 18Mar 14Mar 10Mar 5Feb 28Feb 19
20°FMar 24Mar 15Mar 9Mar 4Feb 28Feb 21Feb 16Feb 9Jan 31
16°FMar 9Mar 1Feb 21Feb 14Feb 7Feb 2Jan 28Jan 19Jan 9

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 3Oct 7Oct 10Oct 12Oct 15Oct 17Oct 20Oct 24Oct 28
32°FOct 10Oct 15Oct 19Oct 21Oct 24Oct 26Oct 29Nov 1Nov 5
28°FOct 19Oct 24Oct 28Oct 31Nov 2Nov 5Nov 8Nov 12Nov 18
24°FOct 30Nov 3Nov 8Nov 11Nov 14Nov 18Nov 23Nov 28Dec 4
20°FNov 12Nov 18Nov 25Nov 30Dec 2Dec 6Dec 14Dec 23Jan 1
16°FNov 28Dec 3Dec 10Dec 18Dec 23Dec 29Jan 1Jan 8Jan 17

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°F193186181177173169165161155
32°F216208203198193190185180173
28°F244234227223218213208202195
24°F276266259253248242236229217
20°F312301293285278272266257248
16°F346334327321313305298289276

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
98% 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
3,591
Cooling degree days, base 65°F
1,492
Growing degree days, base 40°F
7,375
Growing degree days, base 45°F
5,883
Growing degree days, base 50°F
4,545
Growing degree days, base 55°F
3,373
Growing degree days, base 60°F
2,355

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January800029
February610141
March4515131
April22435289
May62138542
June3301748
July1407871
August0369834
September24196623
October21538312
November500384
December703042

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 17.7 km from Madisonville. 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 USC00408886 (Tellico Plains). Public domain.