Daviess County climate

Daviess County Frost Dates and Growing Season

NOAA 1991-2020 normals for Calhoun Lock 2, 27.3 km from Daviess County, elevation 402 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Calhoun Lock 2. 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 2 and the first fall freeze around November 1, a growing season of about 211 days.

Median at 36°F
last April 14, first October 23
Median at 32°F
last April 2, first November 1
Median at 28°F
last March 23, 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°FApr 30Apr 24Apr 20Apr 17Apr 14Apr 11Apr 7Apr 2Mar 28
32°FApr 20Apr 14Apr 10Apr 6Apr 2Mar 31Mar 27Mar 23Mar 17
28°FApr 10Apr 3Mar 30Mar 26Mar 23Mar 19Mar 15Mar 10Mar 4
24°FMar 29Mar 22Mar 17Mar 13Mar 9Mar 5Mar 1Feb 25Feb 16
20°FMar 17Mar 11Mar 6Mar 2Feb 27Feb 22Feb 16Feb 9Feb 3
16°FMar 8Mar 1Feb 25Feb 19Feb 11Feb 6Feb 2Jan 26Jan 16

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 10Oct 15Oct 18Oct 20Oct 23Oct 25Oct 28Oct 30Nov 3
32°FOct 19Oct 24Oct 27Oct 30Nov 1Nov 3Nov 6Nov 9Nov 15
28°FOct 29Nov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 23Nov 30
24°FNov 6Nov 11Nov 14Nov 17Nov 21Nov 25Dec 1Dec 5Dec 12
20°FNov 13Nov 18Nov 24Nov 28Dec 2Dec 7Dec 14Dec 21Dec 28
16°FNov 20Nov 29Dec 4Dec 11Dec 20Dec 26Dec 30Jan 5Jan 14

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°F213206200195191187182177169
32°F234226221216211207203197191
28°F261251245239235230224217209
24°F286277269263258252247241233
20°F313302295288280273267260251
16°F337327319313306301293284273

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
99% 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
4,231
Cooling degree days, base 65°F
1,416
Growing degree days, base 40°F
6,935
Growing degree days, base 45°F
5,542
Growing degree days, base 50°F
4,293
Growing degree days, base 55°F
3,194
Growing degree days, base 60°F
2,236

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January951011
February754121
March557488
April25027261
May68124521
June3287735
July0388852
August1357821
September28188611
October23240292
November560263
December828018

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 27.3 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 USC00151227 (Calhoun Lock 2). Public domain.