Middlesboro climate

Middlesboro Frost Dates and Growing Season

NOAA 1991-2020 normals for Tazewell, 21.2 km from Middlesboro, elevation 1365 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Tazewell. 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 23 and the first fall freeze around October 19, a growing season of about 177 days.

Median at 36°F
last May 5, first October 11
Median at 32°F
last April 23, first October 19
Median at 28°F
last April 10, first October 28

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 14May 10May 7May 5May 1Apr 29Apr 25Apr 20
32°FMay 11May 4Apr 30Apr 27Apr 23Apr 20Apr 17Apr 14Apr 9
28°FApr 26Apr 20Apr 16Apr 13Apr 10Apr 7Apr 4Apr 1Mar 26
24°FApr 12Apr 7Apr 3Apr 1Mar 30Mar 26Mar 23Mar 18Mar 12
20°FApr 1Mar 28Mar 23Mar 20Mar 16Mar 13Mar 7Mar 2Feb 23
16°FMar 24Mar 16Mar 11Mar 6Mar 2Feb 25Feb 18Feb 10Feb 3

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 1Oct 4Oct 6Oct 9Oct 11Oct 13Oct 16Oct 19Oct 23
32°FOct 8Oct 12Oct 14Oct 16Oct 19Oct 21Oct 24Oct 27Nov 1
28°FOct 15Oct 19Oct 22Oct 25Oct 28Oct 30Nov 1Nov 4Nov 8
24°FOct 23Oct 28Nov 1Nov 3Nov 5Nov 8Nov 12Nov 16Nov 21
20°FNov 2Nov 7Nov 11Nov 14Nov 17Nov 21Nov 25Dec 1Dec 6
16°FNov 12Nov 18Nov 24Nov 28Dec 2Dec 5Dec 12Dec 19Dec 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°F177170166162158155151147139
32°F198190185181177173169163156
28°F220213208204199194190185177
24°F246236231227222218213209202
20°F275266259254248243238232224
16°F308297290283276270264258249

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
4,786
Cooling degree days, base 65°F
893
Growing degree days, base 40°F
5,949
Growing degree days, base 45°F
4,624
Growing degree days, base 50°F
3,464
Growing degree days, base 55°F
2,461
Growing degree days, base 60°F
1,602

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January98105
February78509
March639049
April3506170
May13256396
June16177610
July1280744
August2250713
September51113512
October31712205
November633040
December879010

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 21.2 km from Middlesboro. 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 USC00408868 (Tazewell). Public domain.