Warrick County climate

Warrick County Frost Dates and Growing Season

NOAA 1991-2020 normals for Boonville 1S, 6.9 km from Warrick County, elevation 400 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Boonville 1S. 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 12 and the first fall freeze around October 25, a growing season of about 196 days.

Median at 36°F
last April 23, first October 16
Median at 32°F
last April 12, first October 25
Median at 28°F
last March 30, first November 3

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 10May 4Apr 30Apr 26Apr 23Apr 20Apr 17Apr 13Apr 8
32°FApr 28Apr 22Apr 18Apr 15Apr 12Apr 9Apr 6Apr 1Mar 28
28°FApr 14Apr 9Apr 5Apr 2Mar 30Mar 28Mar 24Mar 20Mar 14
24°FApr 4Mar 30Mar 26Mar 22Mar 19Mar 16Mar 12Mar 7Mar 1
20°FMar 25Mar 19Mar 15Mar 11Mar 8Mar 3Feb 28Feb 24Feb 17
16°FMar 15Mar 9Mar 4Feb 28Feb 24Feb 21Feb 15Feb 8Feb 1

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 3Oct 8Oct 11Oct 14Oct 16Oct 19Oct 21Oct 23Oct 27
32°FOct 12Oct 17Oct 21Oct 23Oct 25Oct 28Oct 30Nov 1Nov 5
28°FOct 22Oct 27Oct 30Nov 1Nov 3Nov 5Nov 9Nov 13Nov 20
24°FNov 2Nov 5Nov 8Nov 12Nov 15Nov 19Nov 23Nov 27Dec 3
20°FNov 9Nov 14Nov 18Nov 23Nov 26Dec 1Dec 3Dec 8Dec 16
16°FNov 18Nov 26Nov 30Dec 4Dec 8Dec 13Dec 18Dec 24Dec 31

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°F193187182178175171166162155
32°F216208204200196192187182175
28°F238231226222218214210205198
24°F268257251245240236232226219
20°F292282275270264259253246239
16°F317306300295289283277270262

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
4,277
Cooling degree days, base 65°F
1,491
Growing degree days, base 40°F
7,009
Growing degree days, base 45°F
5,631
Growing degree days, base 50°F
4,391
Growing degree days, base 55°F
3,287
Growing degree days, base 60°F
2,319

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January969011
February756022
March561592
April24333274
May69142538
June4316762
July0411876
August1362826
September34183600
October23236293
November555379
December853018

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 6.9 km from Warrick 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 USC00120852 (Boonville 1S). Public domain.