Sparta climate

Sparta Frost Dates and Growing Season

NOAA 1991-2020 normals for Milledgeville, 33.3 km from Sparta, elevation 368 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Milledgeville. 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 March 25 and the first fall freeze around November 9, a growing season of about 231 days.

Median at 36°F
last April 6, first November 1
Median at 32°F
last March 25, first November 9
Median at 28°F
last March 9, first November 21

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°FApr 21Apr 16Apr 12Apr 9Apr 6Apr 3Mar 31Mar 26Mar 20
32°FApr 9Apr 4Mar 31Mar 28Mar 25Mar 21Mar 17Mar 12Mar 3
28°FMar 28Mar 23Mar 18Mar 14Mar 9Mar 4Feb 28Feb 21Feb 9
24°FMar 15Mar 8Mar 2Feb 24Feb 18Feb 12Feb 5Jan 31Jan 20
20°FMar 3Feb 18Feb 9Feb 3Jan 31Jan 26Jan 20Jan 13Jan 4
16°FFeb 11Feb 2Jan 31Jan 26Jan 20Jan 15Jan 9Jan 2Dec 27

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 20Oct 24Oct 27Oct 30Nov 1Nov 3Nov 5Nov 8Nov 13
32°FOct 29Nov 1Nov 4Nov 6Nov 9Nov 12Nov 16Nov 20Nov 29
28°FNov 4Nov 9Nov 13Nov 16Nov 21Nov 26Dec 1Dec 5Dec 20
24°FNov 14Nov 22Nov 30Dec 3Dec 8Dec 20Dec 29Jan 4Jan 13
20°FDec 2Dec 10Dec 22Dec 29Jan 2Jan 7Jan 13Jan 20Jan 31
16°FDec 15Dec 24Dec 30Jan 2Jan 10Jan 15Jan 21Jan 27Feb 2

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°F230223217213208205201195189
32°F258249243237231226220215208
28°F296282274267260254248242234
24°F333321311304297289280271259
20°F365354345338333327319306297
16°F365365365365362353344335328

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
99% of years
20°F or colder
86% of years
16°F or colder
51% 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
2,480
Cooling degree days, base 65°F
2,103
Growing degree days, base 40°F
8,838
Growing degree days, base 45°F
7,172
Growing degree days, base 50°F
5,652
Growing degree days, base 55°F
4,301
Growing degree days, base 60°F
3,114

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January606261
February450282
March30919219
April12760387
May22208651
June0398847
July0519984
August0484949
September5307753
October9789461
November33712173
December527385

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 33.3 km from Sparta. 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 USC00095874 (Milledgeville). Public domain.