Oldham County climate

Oldham County Frost Dates and Growing Season

NOAA 1991-2020 normals for Crestwood 4NE, 4.7 km from Oldham County, elevation 780 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Crestwood 4NE. 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 193 days.

Median at 36°F
last April 24, first October 15
Median at 32°F
last April 12, first October 25
Median at 28°F
last March 31, 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 11May 5May 1Apr 28Apr 24Apr 21Apr 18Apr 15Apr 10
32°FMay 1Apr 25Apr 20Apr 16Apr 12Apr 8Apr 5Apr 2Mar 29
28°FApr 17Apr 11Apr 6Apr 3Mar 31Mar 29Mar 26Mar 22Mar 17
24°FApr 5Apr 1Mar 29Mar 25Mar 22Mar 19Mar 16Mar 11Mar 3
20°FMar 27Mar 22Mar 18Mar 15Mar 11Mar 7Mar 3Feb 28Feb 18
16°FMar 18Mar 12Mar 7Mar 3Feb 28Feb 24Feb 17Feb 11Feb 5

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 2Oct 6Oct 9Oct 12Oct 15Oct 17Oct 20Oct 23Oct 27
32°FOct 11Oct 16Oct 19Oct 22Oct 25Oct 27Oct 29Nov 1Nov 5
28°FOct 21Oct 26Oct 29Nov 1Nov 3Nov 6Nov 9Nov 13Nov 18
24°FNov 1Nov 4Nov 7Nov 11Nov 14Nov 17Nov 22Nov 27Dec 2
20°FNov 9Nov 14Nov 18Nov 22Nov 27Dec 1Dec 4Dec 8Dec 18
16°FNov 18Nov 26Dec 1Dec 4Dec 8Dec 13Dec 19Dec 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°F191184179175171168164159152
32°F213206201197193188184177170
28°F238231225219214211206200193
24°F264255248243239234228223214
20°F291280273267262257251246237
16°F314303296291284278273267258

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
4,777
Cooling degree days, base 65°F
1,241
Growing degree days, base 40°F
6,430
Growing degree days, base 45°F
5,117
Growing degree days, base 50°F
3,944
Growing degree days, base 55°F
2,911
Growing degree days, base 60°F
2,005

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,027010
February816011
March644467
April30627227
May95106478
June7263706
July1356820
August2315778
September46146551
October29324234
November625150
December916012

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 4.7 km from Oldham 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 USC00151900 (Crestwood 4NE). Public domain.