Carter County climate

Carter County Frost Dates and Growing Season

NOAA 1991-2020 normals for Olive Hill 5NE, 5.5 km from Carter County, elevation 888 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Olive Hill 5NE. 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 18, a growing season of about 174 days.

Median at 36°F
last May 5, first October 9
Median at 32°F
last April 24, first October 18
Median at 28°F
last April 14, first October 27

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

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

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°F173168164160157153149145139
32°F192186182178174170166161154
28°F212206201198195191186182175
24°F241233226222218214210205199
20°F270260254247243239234228222
16°F298288282275270263259252244

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
5,323
Cooling degree days, base 65°F
719
Growing degree days, base 40°F
5,508
Growing degree days, base 45°F
4,254
Growing degree days, base 50°F
3,154
Growing degree days, base 55°F
2,199
Growing degree days, base 60°F
1,380

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,06905
February871011
March729045
April3876156
May14853378
June21141570
July4235696
August8194651
September8879443
October3809162
November682031
December93508

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 5.5 km from Carter 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 USC00156012 (Olive Hill 5NE). Public domain.