Athens climate

Athens Frost Dates and Growing Season

NOAA 1991-2020 normals for Hudson Correctional Facility, 2 km from Athens, elevation 30 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hudson Correctional Facility. 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 25 and the first fall freeze around October 18, a growing season of about 176 days.

Median at 36°F
last May 5, first October 7
Median at 32°F
last April 25, first October 18
Median at 28°F
last April 13, first October 31

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 22May 16May 12May 9May 5May 3Apr 30Apr 27Apr 24
32°FMay 10May 5May 1Apr 28Apr 25Apr 22Apr 19Apr 16Apr 12
28°FApr 28Apr 22Apr 19Apr 15Apr 13Apr 10Apr 7Apr 4Mar 31
24°FApr 16Apr 10Apr 6Apr 3Apr 1Mar 31Mar 28Mar 24Mar 18
20°FApr 5Apr 1Mar 29Mar 26Mar 23Mar 19Mar 16Mar 13Mar 8
16°FMar 30Mar 25Mar 21Mar 17Mar 14Mar 10Mar 7Mar 3Feb 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°FSep 26Oct 1Oct 3Oct 5Oct 7Oct 9Oct 12Oct 16Oct 21
32°FOct 4Oct 8Oct 11Oct 14Oct 18Oct 21Oct 24Oct 28Nov 1
28°FOct 14Oct 20Oct 24Oct 28Oct 31Nov 2Nov 5Nov 9Nov 13
24°FOct 26Nov 1Nov 4Nov 8Nov 11Nov 15Nov 18Nov 21Nov 26
20°FNov 7Nov 13Nov 17Nov 21Nov 24Nov 27Dec 1Dec 3Dec 9
16°FNov 22Nov 28Dec 1Dec 3Dec 5Dec 9Dec 13Dec 18Dec 24

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°F172166162157153150146141134
32°F197190185180176173168163156
28°F219212208204200196191187179
24°F242234229225221218214209202
20°F267260255250246241236230222
16°F288280275271266261256251244

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
5,829
Cooling degree days, base 65°F
813
Growing degree days, base 40°F
5,360
Growing degree days, base 45°F
4,179
Growing degree days, base 50°F
3,138
Growing degree days, base 55°F
2,225
Growing degree days, base 60°F
1,444

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,19001
February1,01100
March839016
April44910112
May16048358
June25160585
July1279742
August5225685
September8685450
October3657161
November684027
December1,01402

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 2 km from Athens. 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 USC00304025 (Hudson Correctional Facility). Public domain.