Athens climate

Athens Frost Dates and Growing Season

NOAA 1991-2020 normals for Athens 4SW, 7.2 km from Athens, elevation 594 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Athens 4SW. 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 19 and the first fall freeze around October 19, a growing season of about 181 days.

Median at 36°F
last April 30, first October 9
Median at 32°F
last April 19, first October 19
Median at 28°F
last April 8, first October 30

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 14May 9May 6May 2Apr 30Apr 27Apr 24Apr 21Apr 17
32°FMay 4Apr 29Apr 25Apr 22Apr 19Apr 16Apr 14Apr 10Apr 6
28°FApr 23Apr 17Apr 14Apr 11Apr 8Apr 5Apr 2Mar 31Mar 24
24°FApr 12Apr 7Apr 3Apr 1Mar 30Mar 25Mar 21Mar 17Mar 11
20°FApr 2Mar 29Mar 24Mar 20Mar 17Mar 14Mar 10Mar 6Feb 28
16°FMar 25Mar 19Mar 14Mar 11Mar 8Mar 4Mar 1Feb 25Feb 17

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°FSep 25Sep 30Oct 3Oct 6Oct 9Oct 12Oct 15Oct 18Oct 22
32°FOct 5Oct 10Oct 13Oct 16Oct 19Oct 21Oct 24Oct 27Oct 31
28°FOct 14Oct 20Oct 24Oct 27Oct 30Nov 1Nov 4Nov 8Nov 17
24°FOct 28Nov 1Nov 4Nov 7Nov 11Nov 15Nov 19Nov 24Nov 30
20°FNov 6Nov 10Nov 15Nov 19Nov 23Nov 27Dec 1Dec 5Dec 10
16°FNov 13Nov 19Nov 25Nov 29Dec 2Dec 5Dec 9Dec 14Dec 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°F180173169165161156152147141
32°F201194190185181177172167159
28°F225218212208204199195189181
24°F251243237232228223218213206
20°F274266258254250245241235227
16°F293283278272268263257251243

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
5,632
Cooling degree days, base 65°F
941
Growing degree days, base 40°F
5,704
Growing degree days, base 45°F
4,489
Growing degree days, base 50°F
3,409
Growing degree days, base 55°F
2,452
Growing degree days, base 60°F
1,620

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,20902
February96306
March748140
April40310153
May14668393
June19206637
July2294758
August8240697
September72103484
October35417189
November671145
December1,03706

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 Athens. 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 USC00110306 (Athens 4SW). Public domain.