Concord climate

Concord Frost Dates and Growing Season

NOAA 1991-2020 normals for Appomattox, 13.2 km from Concord, elevation 850 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Appomattox. 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 7 and the first fall freeze around November 1, a growing season of about 206 days.

Median at 36°F
last April 22, first October 24
Median at 32°F
last April 7, first November 1
Median at 28°F
last March 28, first November 10

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 11May 4Apr 30Apr 25Apr 22Apr 18Apr 15Apr 10Apr 4
32°FApr 26Apr 19Apr 14Apr 10Apr 7Apr 4Apr 1Mar 29Mar 23
28°FApr 11Apr 6Apr 2Mar 31Mar 28Mar 24Mar 20Mar 16Mar 10
24°FApr 3Mar 29Mar 23Mar 19Mar 15Mar 12Mar 8Mar 3Feb 25
20°FMar 24Mar 17Mar 13Mar 9Mar 4Feb 28Feb 22Feb 14Feb 6
16°FMar 15Mar 7Feb 28Feb 22Feb 15Feb 8Feb 3Jan 30Jan 21

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 11Oct 15Oct 19Oct 21Oct 24Oct 26Oct 29Nov 1Nov 4
32°FOct 19Oct 24Oct 28Oct 30Nov 1Nov 3Nov 6Nov 9Nov 14
28°FOct 28Nov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 21Nov 28
24°FNov 5Nov 10Nov 14Nov 17Nov 20Nov 25Dec 1Dec 4Dec 15
20°FNov 13Nov 19Nov 25Dec 1Dec 6Dec 11Dec 20Dec 27Jan 6
16°FNov 30Dec 8Dec 15Dec 24Dec 30Jan 2Jan 9Jan 16Jan 26

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°F204197192187183179175168161
32°F228220216211206202197192183
28°F252243237233229224219214207
24°F280269261255251245239234226
20°F311300292284277271264257246
16°F342332322315308303295287274

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
98% 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
4,279
Cooling degree days, base 65°F
1,165
Growing degree days, base 40°F
6,531
Growing degree days, base 45°F
5,137
Growing degree days, base 50°F
3,905
Growing degree days, base 55°F
2,830
Growing degree days, base 60°F
1,917

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January90408
February729017
March595268
April28822224
May10981439
June13238675
July1354818
August2303766
September42141549
October25423255
November549167
December794020

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 13.2 km from Concord. 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 USC00440243 (Appomattox). Public domain.