Clark County climate

Clark County Frost Dates and Growing Season

NOAA 1991-2020 normals for Arkadelphia 2 N, 14.9 km from Clark County, elevation 196 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Arkadelphia 2 N. 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 March 26 and the first fall freeze around November 4, a growing season of about 225 days.

Median at 36°F
last April 6, first October 27
Median at 32°F
last March 26, first November 4
Median at 28°F
last March 11, first November 16

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

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 15Oct 19Oct 22Oct 24Oct 27Oct 29Nov 1Nov 4Nov 9
32°FOct 23Oct 27Oct 31Nov 2Nov 4Nov 7Nov 10Nov 16Nov 21
28°FNov 1Nov 5Nov 8Nov 12Nov 16Nov 20Nov 24Nov 30Dec 5
24°FNov 8Nov 14Nov 19Nov 24Nov 28Dec 3Dec 7Dec 14Dec 25
20°FNov 21Nov 28Dec 4Dec 11Dec 19Dec 25Dec 31Jan 4Jan 15
16°FDec 7Dec 19Dec 26Dec 31Jan 3Jan 7Jan 13Jan 19Feb 1

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°F223216212207202198194188182
32°F250241234230225220215209201
28°F275266261253249244238232221
24°F307297288281275270264258248
20°F345334325317309303296287273
16°F365365358350342335329319305

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
97% of years
16°F or colder
74% 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
2,814
Cooling degree days, base 65°F
2,196
Growing degree days, base 40°F
8,675
Growing degree days, base 45°F
7,069
Growing degree days, base 50°F
5,618
Growing degree days, base 55°F
4,325
Growing degree days, base 60°F
3,182

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January691034
February525161
March34216197
April12166400
May20215660
June0422871
July05391,004
August0521986
September7316759
October11990441
November3799149
December609256

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 14.9 km from Clark 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 USC00030220 (Arkadelphia 2 N). Public domain.