Clarkesville climate

Clarkesville Frost Dates and Growing Season

NOAA 1991-2020 normals for Clarkesville, 1.7 km from Clarkesville, elevation 1370 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Clarkesville. 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 26, a growing season of about 198 days.

Median at 36°F
last April 25, first October 17
Median at 32°F
last April 11, first October 26
Median at 28°F
last March 29, 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 11May 6May 2Apr 29Apr 25Apr 22Apr 18Apr 14Apr 8
32°FMay 1Apr 25Apr 19Apr 15Apr 11Apr 7Apr 4Mar 31Mar 25
28°FApr 16Apr 9Apr 4Apr 1Mar 29Mar 26Mar 21Mar 17Mar 9
24°FApr 2Mar 27Mar 22Mar 18Mar 14Mar 11Mar 6Feb 28Feb 22
20°FMar 20Mar 14Mar 9Mar 4Feb 28Feb 23Feb 18Feb 8Jan 31
16°FMar 10Mar 2Feb 24Feb 17Feb 11Feb 4Jan 29Jan 19Jan 8

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 7Oct 11Oct 13Oct 15Oct 17Oct 20Oct 23Oct 27Oct 31
32°FOct 14Oct 18Oct 21Oct 24Oct 26Oct 29Nov 1Nov 3Nov 8
28°FOct 23Oct 28Nov 1Nov 2Nov 5Nov 9Nov 13Nov 18Nov 26
24°FNov 3Nov 8Nov 12Nov 16Nov 21Nov 26Dec 1Dec 5Dec 15
20°FNov 14Nov 22Nov 28Dec 1Dec 6Dec 11Dec 19Dec 28Jan 4
16°FDec 1Dec 8Dec 14Dec 23Dec 30Jan 3Jan 9Jan 18Jan 31

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°F199192186183179174169164158
32°F221213207203198194188184177
28°F249239233227222217213207198
24°F283272264258252247241234223
20°F320306298290283278271262252
16°F356341332324317309301292281

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
95% 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
3,595
Cooling degree days, base 65°F
1,295
Growing degree days, base 40°F
7,089
Growing degree days, base 45°F
5,585
Growing degree days, base 50°F
4,253
Growing degree days, base 55°F
3,102
Growing degree days, base 60°F
2,117

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January767021
February619026
March4763107
April22720259
May71102497
June5251696
July0369834
August0341806
September22178606
October21529295
November490279
December704028

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 1.7 km from Clarkesville. 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 USC00091965 (Clarkesville). Public domain.