Aiken climate

Aiken Frost Dates and Growing Season

NOAA 1991-2020 normals for Aiken 5SE, 7.8 km from Aiken, elevation 492 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Aiken 5SE. 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 21 and the first fall freeze around November 7, a growing season of about 232 days.

Median at 36°F
last April 1, first October 30
Median at 32°F
last March 21, first November 7
Median at 28°F
last March 9, first November 19

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 18Apr 12Apr 7Apr 4Apr 1Mar 29Mar 26Mar 22Mar 16
32°FApr 6Apr 1Mar 28Mar 25Mar 21Mar 18Mar 14Mar 10Mar 2
28°FMar 28Mar 23Mar 17Mar 14Mar 9Mar 4Feb 28Feb 23Feb 14
24°FMar 18Mar 11Mar 4Feb 28Feb 23Feb 16Feb 9Feb 2Jan 24
20°FMar 7Feb 27Feb 16Feb 8Feb 3Jan 30Jan 22Jan 14Jan 1
16°FFeb 27Feb 12Feb 3Jan 30Jan 24Jan 18Jan 12Jan 4Dec 24

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 16Oct 21Oct 24Oct 27Oct 30Nov 1Nov 3Nov 6Nov 10
32°FOct 25Oct 30Nov 1Nov 4Nov 7Nov 9Nov 12Nov 17Nov 24
28°FNov 3Nov 8Nov 12Nov 16Nov 19Nov 25Dec 1Dec 5Dec 14
24°FNov 13Nov 19Nov 25Dec 1Dec 5Dec 10Dec 18Dec 27Jan 5
20°FNov 26Dec 5Dec 12Dec 21Dec 28Jan 3Jan 8Jan 15Jan 30
16°FDec 9Dec 22Dec 30Jan 4Jan 10Jan 16Jan 20Jan 30Feb 15

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°F234225219215211206202196188
32°F259249243237232227223217208
28°F288275267262256251245239230
24°F323309301293286280273264253
20°F356342334328320311304294283
16°F365365365365354344335327309

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
90% of years
16°F or colder
56% 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
2,486
Cooling degree days, base 65°F
2,186
Growing degree days, base 40°F
8,919
Growing degree days, base 45°F
7,257
Growing degree days, base 50°F
5,739
Growing degree days, base 55°F
4,389
Growing degree days, base 60°F
3,202

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January608154
February451180
March30616220
April10680429
May16238687
June0428877
July05361,001
August0479944
September5308753
October10288455
November34310170
December550169

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 7.8 km from Aiken. 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 USC00380074 (Aiken 5SE). Public domain.