Scotland County climate

Scotland County Frost Dates and Growing Season

NOAA 1991-2020 normals for Memphis, 3 km from Scotland County, elevation 770 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Memphis. 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 23 and the first fall freeze around October 17, a growing season of about 176 days.

Median at 36°F
last May 3, first October 5
Median at 32°F
last April 23, first October 17
Median at 28°F
last April 11, 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 16May 11May 8May 5May 3May 1Apr 28Apr 24Apr 19
32°FMay 6May 2Apr 29Apr 26Apr 23Apr 20Apr 16Apr 13Apr 8
28°FApr 27Apr 21Apr 17Apr 14Apr 11Apr 8Apr 5Apr 2Mar 27
24°FApr 17Apr 10Apr 6Apr 3Apr 1Mar 29Mar 24Mar 20Mar 14
20°FApr 7Apr 1Mar 29Mar 24Mar 21Mar 17Mar 14Mar 10Mar 5
16°FMar 29Mar 22Mar 18Mar 14Mar 11Mar 9Mar 5Mar 2Feb 25

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 21Sep 27Sep 30Oct 3Oct 5Oct 9Oct 12Oct 15Oct 19
32°FOct 2Oct 8Oct 11Oct 14Oct 17Oct 19Oct 22Oct 25Oct 29
28°FOct 13Oct 18Oct 22Oct 24Oct 26Oct 29Oct 31Nov 3Nov 7
24°FOct 24Oct 28Oct 31Nov 1Nov 4Nov 6Nov 9Nov 12Nov 18
20°FNov 1Nov 4Nov 7Nov 10Nov 13Nov 16Nov 20Nov 25Dec 1
16°FNov 8Nov 12Nov 17Nov 20Nov 24Nov 27Dec 1Dec 5Dec 11

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°F173167163158155151148143135
32°F195188183179176172167162154
28°F216210205201197193189184177
24°F240233226220217213209205197
20°F261253247242238233228223214
16°F281272266261256251247241234

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
6,149
Cooling degree days, base 65°F
958
Growing degree days, base 40°F
5,521
Growing degree days, base 45°F
4,357
Growing degree days, base 50°F
3,317
Growing degree days, base 55°F
2,400
Growing degree days, base 60°F
1,612

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,29700
February1,04903
March801136
April4386125
May17459360
June21201630
July2315778
August6260719
September94101461
October38314175
November764028
December1,12103

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 km from Scotland County. 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 USC00235492 (Memphis). Public domain.