Lawrence County climate

Lawrence County Frost Dates and Growing Season

NOAA 1991-2020 normals for Charley 2 Sw, 12.2 km from Lawrence County, elevation 740 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Charley 2 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 April 24 and the first fall freeze around October 17, a growing season of about 174 days.

Median at 36°F
last May 6, first October 9
Median at 32°F
last April 24, first October 17
Median at 28°F
last April 12, first October 26

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

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 28Oct 1Oct 4Oct 6Oct 9Oct 11Oct 13Oct 15Oct 20
32°FOct 6Oct 10Oct 12Oct 15Oct 17Oct 20Oct 22Oct 25Oct 29
28°FOct 13Oct 18Oct 21Oct 23Oct 26Oct 29Oct 31Nov 2Nov 7
24°FOct 24Oct 29Oct 31Nov 1Nov 4Nov 7Nov 10Nov 13Nov 21
20°FNov 1Nov 6Nov 9Nov 12Nov 15Nov 19Nov 24Nov 30Dec 6
16°FNov 9Nov 15Nov 20Nov 24Nov 29Dec 2Dec 6Dec 12Dec 21

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°F174168164160156152148144137
32°F191185181177174170166160153
28°F215209204200196192187182174
24°F239230225221217214210206200
20°F265256250245241236232226218
16°F296284277271265260254248239

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
4,853
Cooling degree days, base 65°F
875
Growing degree days, base 40°F
5,895
Growing degree days, base 45°F
4,586
Growing degree days, base 50°F
3,436
Growing degree days, base 55°F
2,437
Growing degree days, base 60°F
1,577

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January98708
February804010
March660154
April33712190
May13761393
June18180612
July1278742
August4238699
September5894487
October32912195
November639035
December880011

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 12.2 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 USC00151517 (Charley 2 Sw). Public domain.