Davidson County climate

Davidson County Frost Dates and Growing Season

NOAA 1991-2020 normals for Lexington, 7.2 km from Davidson County, elevation 760 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lexington. 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 11 and the first fall freeze around October 28, a growing season of about 199 days.

Median at 36°F
last April 23, first October 19
Median at 32°F
last April 11, first October 28
Median at 28°F
last March 30, first November 5

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 10May 4Apr 30Apr 26Apr 23Apr 21Apr 18Apr 14Apr 9
32°FApr 26Apr 21Apr 17Apr 14Apr 11Apr 8Apr 5Apr 1Mar 28
28°FApr 14Apr 8Apr 5Apr 2Mar 30Mar 27Mar 23Mar 20Mar 14
24°FApr 3Mar 28Mar 24Mar 20Mar 18Mar 14Mar 10Mar 4Feb 26
20°FMar 23Mar 16Mar 11Mar 6Mar 2Feb 27Feb 22Feb 14Feb 2
16°FMar 9Mar 2Feb 26Feb 19Feb 11Feb 3Jan 30Jan 24Jan 13

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 11Oct 14Oct 16Oct 19Oct 22Oct 24Oct 27Oct 31
32°FOct 14Oct 18Oct 22Oct 25Oct 28Oct 30Nov 1Nov 4Nov 7
28°FOct 25Oct 29Nov 1Nov 3Nov 5Nov 8Nov 11Nov 15Nov 20
24°FNov 4Nov 8Nov 11Nov 14Nov 18Nov 22Nov 26Dec 1Dec 8
20°FNov 14Nov 20Nov 26Dec 1Dec 3Dec 8Dec 15Dec 23Jan 3
16°FDec 1Dec 6Dec 13Dec 19Dec 26Jan 1Jan 5Jan 12Jan 20

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°F197191187183178174170165158
32°F218210206202199195190186179
28°F245236229225221217213208202
24°F274266258252247242236231224
20°F309300293286278273266259249
16°F347334326318309303297288277

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
97% 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
3,498
Cooling degree days, base 65°F
1,455
Growing degree days, base 40°F
7,361
Growing degree days, base 45°F
5,852
Growing degree days, base 50°F
4,507
Growing degree days, base 55°F
3,328
Growing degree days, base 60°F
2,311

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January783019
February608032
March4575118
April20233297
May56127537
June5293738
July0406871
August0358823
September21193622
October19037324
November474394
December703133

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 7.2 km from Davidson County. 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 USC00314970 (Lexington). Public domain.