Butler County climate

Butler County Frost Dates and Growing Season

NOAA 1991-2020 normals for Greenville, 8 km from Butler County, elevation 342 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Greenville. 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 28 and the first fall freeze around November 7, a growing season of about 224 days.

Median at 36°F
last April 8, first October 29
Median at 32°F
last March 28, first November 7
Median at 28°F
last March 13, first November 19

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 25Apr 20Apr 15Apr 12Apr 8Apr 5Apr 2Mar 29Mar 23
32°FApr 15Apr 8Apr 3Mar 31Mar 28Mar 24Mar 20Mar 15Mar 8
28°FApr 1Mar 26Mar 22Mar 17Mar 13Mar 9Mar 4Feb 27Feb 19
24°FMar 19Mar 12Mar 7Mar 2Feb 27Feb 21Feb 14Feb 4Jan 26
20°FMar 8Mar 1Feb 22Feb 13Feb 5Jan 31Jan 25Jan 17Jan 5
16°FFeb 28Feb 12Feb 4Jan 31Jan 25Jan 19Jan 12Jan 5Dec 28

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 18Oct 21Oct 24Oct 26Oct 29Nov 1Nov 3Nov 6Nov 11
32°FOct 25Oct 30Nov 1Nov 4Nov 7Nov 10Nov 13Nov 18Nov 25
28°FNov 2Nov 7Nov 11Nov 15Nov 19Nov 23Nov 28Dec 2Dec 7
24°FNov 11Nov 18Nov 24Nov 30Dec 2Dec 7Dec 14Dec 25Jan 2
20°FNov 24Dec 2Dec 8Dec 14Dec 24Dec 31Jan 5Jan 13Jan 27
16°FDec 6Dec 15Dec 24Dec 31Jan 4Jan 8Jan 14Jan 23Feb 3

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°F223216211206202198194188182
32°F251242235229224219214208201
28°F283271264259252246240233224
24°F318306298290283276268260251
20°F354339331324316309301292278
16°F365365365358347337330322306

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
94% of years
16°F or colder
66% 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
2,257
Cooling degree days, base 65°F
2,090
Growing degree days, base 40°F
9,045
Growing degree days, base 45°F
7,365
Growing degree days, base 50°F
5,807
Growing degree days, base 55°F
4,396
Growing degree days, base 60°F
3,155

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January564382
February4047121
March26522257
April10868414
May18218665
June0381831
July0473938
August0463928
September4323769
October90111490
November31218202
December4935111

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 8 km from Butler 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 USC00013519 (Greenville). Public domain.