Hardin County climate

Hardin County Frost Dates and Growing Season

NOAA 1991-2020 normals for Rosiclare 5NW, 13.7 km from Hardin County, elevation 400 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rosiclare 5NW. 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 19 and the first fall freeze around October 20, a growing season of about 181 days.

Median at 36°F
last May 2, first October 11
Median at 32°F
last April 19, first October 20
Median at 28°F
last April 6, first October 29

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

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°FSep 28Oct 3Oct 6Oct 8Oct 11Oct 13Oct 15Oct 18Oct 21
32°FOct 7Oct 12Oct 15Oct 17Oct 20Oct 22Oct 24Oct 27Oct 30
28°FOct 16Oct 21Oct 24Oct 27Oct 29Oct 31Nov 1Nov 5Nov 9
24°FOct 28Oct 31Nov 2Nov 5Nov 8Nov 11Nov 14Nov 19Nov 27
20°FNov 4Nov 8Nov 12Nov 15Nov 18Nov 23Nov 27Dec 2Dec 8
16°FNov 12Nov 17Nov 21Nov 27Dec 1Dec 5Dec 9Dec 16Dec 24

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°F181174169165161157153148141
32°F201196190185181177173168160
28°F227220214209204200195189180
24°F254245239233229224219213205
20°F279269262257252247242236229
16°F305294286279274269264256248

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
4,803
Cooling degree days, base 65°F
1,131
Growing degree days, base 40°F
6,302
Growing degree days, base 45°F
4,981
Growing degree days, base 50°F
3,804
Growing degree days, base 55°F
2,770
Growing degree days, base 60°F
1,878

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,02909
February822014
March629373
April31619211
May11884434
June11229667
July1336800
August2298761
September56139534
October30023229
November612260
December907012

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 13.7 km from Hardin 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 USC00117487 (Rosiclare 5NW). Public domain.