Davidson County climate

Davidson County Frost Dates and Growing Season

NOAA 1991-2020 normals for Shelby Bottoms Nature, 4.7 km from Davidson County, elevation 405 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Shelby Bottoms Nature. 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 1 and the first fall freeze around October 31, a growing season of about 213 days.

Median at 36°F
last April 14, first October 22
Median at 32°F
last April 1, first October 31
Median at 28°F
last March 20, first November 9

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 4Apr 27Apr 21Apr 17Apr 14Apr 11Apr 8Apr 4Mar 31
32°FApr 16Apr 11Apr 7Apr 4Apr 1Mar 30Mar 25Mar 22Mar 16
28°FApr 5Apr 1Mar 28Mar 23Mar 20Mar 16Mar 13Mar 8Mar 2
24°FMar 27Mar 21Mar 16Mar 13Mar 8Mar 4Feb 28Feb 26Feb 19
20°FMar 17Mar 11Mar 5Mar 1Feb 27Feb 23Feb 17Feb 12Feb 5
16°FMar 8Feb 28Feb 24Feb 19Feb 14Feb 10Feb 5Jan 31Jan 23

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 9Oct 13Oct 17Oct 20Oct 22Oct 24Oct 27Oct 30Nov 3
32°FOct 18Oct 22Oct 25Oct 28Oct 31Nov 1Nov 5Nov 8Nov 13
28°FOct 26Oct 31Nov 3Nov 5Nov 9Nov 12Nov 15Nov 19Nov 25
24°FNov 5Nov 12Nov 15Nov 18Nov 22Nov 26Dec 1Dec 4Dec 10
20°FNov 15Nov 22Nov 28Dec 1Dec 5Dec 9Dec 13Dec 20Dec 27
16°FNov 30Dec 6Dec 10Dec 16Dec 23Dec 27Dec 31Jan 5Jan 14

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°F210204198194190185181176168
32°F232225221216213208204199192
28°F260249243239235229225219212
24°F282275269263258253248241232
20°F308300293287281277271265255
16°F335327320314308303297289279

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
3,648
Cooling degree days, base 65°F
1,587
Growing degree days, base 40°F
7,486
Growing degree days, base 45°F
5,999
Growing degree days, base 50°F
4,655
Growing degree days, base 55°F
3,470
Growing degree days, base 60°F
2,457

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January844018
February652040
March4647129
April20142310
May61148553
June1310759
July0422887
August0397862
September22215643
October19142327
November479494
December732034

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 4.7 km from Davidson County. 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 USC00408238 (Shelby Bottoms Nature). Public domain.