Daviess County climate

Daviess County Frost Dates and Growing Season

NOAA 1991-2020 normals for Washington 1 W, 12.5 km from Daviess County, elevation 482 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Washington 1 W. 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 10 and the first fall freeze around October 25, a growing season of about 197 days.

Median at 36°F
last April 22, first October 15
Median at 32°F
last April 10, first October 25
Median at 28°F
last March 30, first November 4

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 8May 2Apr 29Apr 25Apr 22Apr 19Apr 16Apr 13Apr 8
32°FApr 27Apr 21Apr 17Apr 14Apr 10Apr 7Apr 4Mar 31Mar 27
28°FApr 15Apr 10Apr 5Apr 1Mar 30Mar 28Mar 24Mar 20Mar 14
24°FApr 4Mar 30Mar 27Mar 24Mar 20Mar 17Mar 13Mar 8Mar 1
20°FMar 26Mar 19Mar 15Mar 11Mar 8Mar 4Mar 1Feb 25Feb 17
16°FMar 17Mar 11Mar 6Mar 3Feb 26Feb 23Feb 17Feb 10Feb 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 1Oct 7Oct 11Oct 13Oct 15Oct 18Oct 21Oct 23Oct 28
32°FOct 11Oct 17Oct 20Oct 23Oct 25Oct 28Oct 30Nov 2Nov 7
28°FOct 22Oct 27Oct 31Nov 1Nov 4Nov 7Nov 10Nov 14Nov 20
24°FNov 1Nov 5Nov 9Nov 12Nov 15Nov 19Nov 23Nov 27Dec 3
20°FNov 9Nov 15Nov 19Nov 24Nov 27Dec 1Dec 3Dec 8Dec 16
16°FNov 17Nov 25Nov 30Dec 3Dec 7Dec 11Dec 18Dec 24Dec 30

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°F194187182178174169165160153
32°F216210205201197192188182174
28°F240233228224220215211206197
24°F267259253247243237232227218
20°F290280274269264259254247240
16°F313304297291285280273266256

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
4,494
Cooling degree days, base 65°F
1,370
Growing degree days, base 40°F
6,775
Growing degree days, base 45°F
5,421
Growing degree days, base 50°F
4,206
Growing degree days, base 55°F
3,124
Growing degree days, base 60°F
2,178

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,01808
February797018
March589584
April27028251
May79132519
June5289733
July0375840
August2333797
September38169581
October24238289
November572273
December882014

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 12.5 km from Daviess 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 USC00129253 (Washington 1 W). Public domain.