Clinton climate

Clinton Frost Dates and Growing Season

NOAA 1991-2020 normals for Clinton, 0.4 km from Clinton, elevation 655 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Clinton. 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 March 29 and the first fall freeze around November 4, a growing season of about 219 days.

Median at 36°F
last April 9, first October 26
Median at 32°F
last March 29, first November 4
Median at 28°F
last March 18, first November 17

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 23Apr 19Apr 15Apr 12Apr 9Apr 6Apr 4Mar 31Mar 27
32°FApr 13Apr 7Apr 3Apr 1Mar 29Mar 26Mar 23Mar 19Mar 14
28°FApr 2Mar 28Mar 25Mar 21Mar 18Mar 15Mar 11Mar 5Feb 27
24°FMar 24Mar 18Mar 14Mar 11Mar 6Mar 1Feb 24Feb 18Feb 7
20°FMar 15Mar 7Mar 1Feb 21Feb 14Feb 7Feb 1Jan 25Jan 14
16°FMar 6Feb 23Feb 11Feb 4Jan 31Jan 23Jan 16Jan 7Dec 29

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 14Oct 17Oct 21Oct 24Oct 26Oct 29Nov 1Nov 4Nov 8
32°FOct 21Oct 26Oct 30Nov 1Nov 4Nov 7Nov 10Nov 14Nov 20
28°FNov 1Nov 6Nov 10Nov 14Nov 17Nov 20Nov 24Nov 30Dec 5
24°FNov 13Nov 18Nov 25Nov 29Dec 1Dec 5Dec 10Dec 19Dec 31
20°FNov 27Dec 3Dec 7Dec 13Dec 21Dec 28Jan 3Jan 11Jan 22
16°FDec 6Dec 11Dec 19Dec 25Jan 1Jan 7Jan 14Jan 20Feb 2

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°F218211207203200196192188181
32°F243235229224219216212207199
28°F271261255248244239235229221
24°F307294287279273267260253244
20°F346333324313305297290282269
16°F365365356346338332323309296

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
97% of years
16°F or colder
79% 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
2,948
Cooling degree days, base 65°F
1,811
Growing degree days, base 40°F
8,145
Growing degree days, base 45°F
6,545
Growing degree days, base 50°F
5,104
Growing degree days, base 55°F
3,834
Growing degree days, base 60°F
2,736

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January677039
February522157
March38810161
April15245350
May37172600
June1358807
July0468933
August0425890
September11273712
October13954384
November3926127
December631045

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 0.4 km from Clinton. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00381814 (Clinton). Public domain.