Edgefield climate

Edgefield Frost Dates and Growing Season

NOAA 1991-2020 normals for Johnston 4 Sw, 8.1 km from Edgefield, elevation 629 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Johnston 4 Sw. 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 26 and the first fall freeze around November 8, a growing season of about 228 days.

Median at 36°F
last April 7, first October 29
Median at 32°F
last March 26, first November 8
Median at 28°F
last March 13, 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 22Apr 18Apr 13Apr 10Apr 7Apr 4Apr 2Mar 28Mar 21
32°FApr 11Apr 6Apr 2Mar 31Mar 26Mar 22Mar 19Mar 14Mar 6
28°FMar 31Mar 25Mar 21Mar 16Mar 13Mar 8Mar 4Feb 27Feb 18
24°FMar 20Mar 12Mar 6Mar 1Feb 26Feb 20Feb 13Feb 6Jan 30
20°FMar 6Feb 27Feb 19Feb 10Feb 4Jan 31Jan 26Jan 16Jan 4
16°FFeb 23Feb 8Feb 2Jan 31Jan 24Jan 17Jan 13Jan 4Dec 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 16Oct 21Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6Nov 11
32°FOct 25Oct 30Nov 2Nov 5Nov 8Nov 11Nov 14Nov 19Nov 28
28°FNov 4Nov 8Nov 12Nov 15Nov 19Nov 24Nov 29Dec 4Dec 12
24°FNov 14Nov 20Nov 26Dec 1Dec 5Dec 10Dec 20Dec 27Jan 4
20°FNov 29Dec 6Dec 13Dec 22Dec 28Jan 1Jan 6Jan 13Jan 25
16°FDec 10Dec 21Dec 28Jan 1Jan 8Jan 13Jan 18Jan 26Feb 5

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°F226219213208204200196192185
32°F254245239233228223218212203
28°F285272265259254249244237229
24°F320307298291284277269261252
20°F357342333326318308303293279
16°F365365365356348340333324307

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
94% of years
16°F or colder
67% 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
2,761
Cooling degree days, base 65°F
1,943
Growing degree days, base 40°F
8,454
Growing degree days, base 45°F
6,836
Growing degree days, base 50°F
5,366
Growing degree days, base 55°F
4,055
Growing degree days, base 60°F
2,911

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January650153
February500268
March35612186
April14659371
May30196631
June1375823
July0491956
August0445910
September9276717
October12274423
November36710158
December579270

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 8.1 km from Edgefield. 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 USC00384607 (Johnston 4 Sw). Public domain.