Benton County climate

Benton County Frost Dates and Growing Season

NOAA 1991-2020 normals for Truman Dam & Rsvr, 11.6 km from Benton County, elevation 754 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Truman Dam & Rsvr. 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 7 and the first fall freeze around October 30, a growing season of about 205 days.

Median at 36°F
last April 19, first October 21
Median at 32°F
last April 7, first October 30
Median at 28°F
last March 29, first November 10

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 3Apr 29Apr 25Apr 22Apr 19Apr 16Apr 13Apr 9Apr 4
32°FApr 22Apr 16Apr 13Apr 10Apr 7Apr 5Apr 1Mar 29Mar 21
28°FApr 11Apr 7Apr 4Apr 1Mar 29Mar 25Mar 21Mar 16Mar 8
24°FApr 3Mar 30Mar 24Mar 20Mar 16Mar 13Mar 8Mar 5Feb 28
20°FMar 23Mar 16Mar 12Mar 9Mar 6Mar 3Feb 28Feb 24Feb 17
16°FMar 14Mar 8Mar 5Mar 2Feb 27Feb 24Feb 18Feb 12Feb 3

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 13Oct 16Oct 19Oct 21Oct 23Oct 26Oct 29Nov 1
32°FOct 16Oct 21Oct 25Oct 27Oct 30Nov 1Nov 4Nov 7Nov 13
28°FOct 28Nov 1Nov 3Nov 6Nov 10Nov 13Nov 16Nov 21Nov 28
24°FNov 4Nov 9Nov 12Nov 17Nov 21Nov 25Nov 29Dec 2Dec 8
20°FNov 13Nov 20Nov 25Nov 29Dec 1Dec 5Dec 10Dec 15Dec 21
16°FNov 24Nov 30Dec 5Dec 10Dec 15Dec 19Dec 23Dec 28Jan 2

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°F202197190187183179175171164
32°F226218212208205201197191184
28°F250242237231226221216212205
24°F276266260254249244240233224
20°F296286280276271267261255246
16°F318307302296291286280274263

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
4,568
Cooling degree days, base 65°F
1,523
Growing degree days, base 40°F
6,848
Growing degree days, base 45°F
5,502
Growing degree days, base 50°F
4,299
Growing degree days, base 55°F
3,235
Growing degree days, base 60°F
2,310

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,01705
February813015
March609373
April30021220
May93112486
June6303747
July0451916
August1405869
September40191602
October24935282
November559375
December882011

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 11.6 km from Benton 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 USC00238466 (Truman Dam & Rsvr). Public domain.