Clinton County climate

Clinton County Frost Dates and Growing Season

NOAA 1991-2020 normals for Renovo, 13.6 km from Clinton County, elevation 660 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Renovo. 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 30 and the first fall freeze around October 22, a growing season of about 173 days.

Median at 36°F
last May 12, first October 8
Median at 32°F
last April 30, first October 22
Median at 28°F
last April 18, first November 2

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 27May 22May 19May 16May 12May 8May 5May 1Apr 27
32°FMay 17May 11May 6May 3Apr 30Apr 27Apr 25Apr 21Apr 17
28°FMay 5Apr 29Apr 24Apr 20Apr 18Apr 15Apr 11Apr 6Apr 1
24°FApr 16Apr 11Apr 7Apr 5Apr 3Apr 1Mar 30Mar 27Mar 21
20°FApr 4Mar 31Mar 30Mar 27Mar 23Mar 21Mar 17Mar 14Mar 8
16°FMar 27Mar 22Mar 19Mar 16Mar 13Mar 11Mar 7Mar 3Feb 27

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 27Oct 1Oct 3Oct 5Oct 8Oct 12Oct 15Oct 19Oct 23
32°FOct 6Oct 10Oct 15Oct 19Oct 22Oct 25Oct 28Nov 1Nov 4
28°FOct 19Oct 24Oct 29Nov 1Nov 2Nov 5Nov 8Nov 11Nov 16
24°FNov 1Nov 5Nov 9Nov 12Nov 15Nov 18Nov 21Nov 24Dec 1
20°FNov 10Nov 15Nov 20Nov 23Nov 27Nov 30Dec 3Dec 9Dec 16
16°FNov 20Nov 26Nov 30Dec 3Dec 9Dec 13Dec 18Dec 23Dec 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°F169163158154150146142136129
32°F193186181177173168164159152
28°F220213207203199194190184176
24°F246238233228224221218214208
20°F273265258253248244240235228
16°F295287281276272266261255247

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
6,168
Cooling degree days, base 65°F
601
Growing degree days, base 40°F
4,880
Growing degree days, base 45°F
3,746
Growing degree days, base 50°F
2,752
Growing degree days, base 55°F
1,896
Growing degree days, base 60°F
1,173

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,19500
February1,01801
March877013
April503386
May21735298
June47116519
July6208666
August12172625
September11061403
October4226124
November731016
December1,02902

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 13.6 km from Clinton 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 USC00367409 (Renovo). Public domain.