Lawrence County climate

Lawrence County Frost Dates and Growing Season

NOAA 1991-2020 normals for Moulton 2, 3.9 km from Lawrence County, elevation 622 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Moulton 2. 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 2 and the first fall freeze around October 31, a growing season of about 209 days.

Median at 36°F
last April 13, first October 21
Median at 32°F
last April 2, first October 31
Median at 28°F
last March 23, first November 8

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

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 8Oct 13Oct 17Oct 19Oct 21Oct 23Oct 26Oct 28Nov 1
32°FOct 18Oct 22Oct 25Oct 28Oct 31Nov 1Nov 4Nov 7Nov 14
28°FOct 27Nov 1Nov 2Nov 5Nov 8Nov 12Nov 16Nov 21Nov 29
24°FNov 4Nov 9Nov 14Nov 17Nov 21Nov 25Nov 30Dec 3Dec 10
20°FNov 14Nov 20Nov 26Dec 1Dec 4Dec 9Dec 19Dec 27Jan 4
16°FNov 28Dec 5Dec 14Dec 22Dec 27Jan 1Jan 6Jan 12Jan 22

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°F207201197193190186182178171
32°F231223218214209206201196190
28°F259249243237232227222216210
24°F287278270265259252247240231
20°F318309300292286280273266257
16°F353340331323317309301293281

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
94% 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
3,334
Cooling degree days, base 65°F
1,610
Growing degree days, base 40°F
7,712
Growing degree days, base 45°F
6,186
Growing degree days, base 50°F
4,808
Growing degree days, base 55°F
3,581
Growing degree days, base 60°F
2,516

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January766033
February593147
March4157154
April18342325
May47147566
June1312760
July0415880
August0397862
September17232664
October17450356
November4526116
December686145

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 3.9 km from Lawrence County. 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 USC00015635 (Moulton 2). Public domain.