Fort Campbell North climate

Fort Campbell North Frost Dates and Growing Season

NOAA 1991-2020 normals for Clarksville Outlaw AP, 5 km from Fort Campbell North, elevation 560 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Clarksville Outlaw AP. 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 6 and the first fall freeze around October 28, a growing season of about 204 days.

Median at 36°F
last April 18, first October 19
Median at 32°F
last April 6, first October 28
Median at 28°F
last March 25, first November 7

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

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 7Oct 11Oct 14Oct 17Oct 19Oct 22Oct 24Oct 27Oct 31
32°FOct 15Oct 20Oct 23Oct 26Oct 28Oct 31Nov 2Nov 5Nov 9
28°FOct 26Oct 31Nov 2Nov 4Nov 7Nov 9Nov 13Nov 17Nov 24
24°FNov 4Nov 8Nov 13Nov 16Nov 18Nov 22Nov 27Dec 1Dec 7
20°FNov 13Nov 18Nov 23Nov 27Dec 1Dec 4Dec 9Dec 15Dec 22
16°FNov 24Dec 1Dec 5Dec 10Dec 16Dec 23Dec 28Jan 2Jan 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°F202195191187183180175170163
32°F226218212207204199195190183
28°F251243237231227223218212205
24°F278269263258253246240234226
20°F307298289282277271265259250
16°F335324315309304298292283272

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
99% 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
3,886
Cooling degree days, base 65°F
1,510
Growing degree days, base 40°F
7,250
Growing degree days, base 45°F
5,805
Growing degree days, base 50°F
4,504
Growing degree days, base 55°F
3,356
Growing degree days, base 60°F
2,358

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January870023
February682136
March5046112
April23334281
May65134535
June2302750
July0409874
August0386851
September28194617
October21640306
November510387
December777031

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 km from Fort Campbell North. 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 USW00003894 (Clarksville Outlaw AP). Public domain.