Sullivan climate

Sullivan Frost Dates and Growing Season

NOAA 1991-2020 normals for Farmersburg TV-2, 16.5 km from Sullivan, elevation 548 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Farmersburg TV-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 8 and the first fall freeze around October 27, a growing season of about 201 days.

Median at 36°F
last April 20, first October 15
Median at 32°F
last April 8, first October 27
Median at 28°F
last March 29, first November 6

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 8May 2Apr 27Apr 23Apr 20Apr 17Apr 13Apr 9Apr 5
32°FApr 24Apr 19Apr 14Apr 10Apr 8Apr 5Apr 2Mar 31Mar 25
28°FApr 12Apr 6Apr 3Mar 31Mar 29Mar 25Mar 21Mar 17Mar 12
24°FApr 2Mar 29Mar 24Mar 20Mar 17Mar 14Mar 10Mar 5Feb 28
20°FMar 24Mar 18Mar 14Mar 10Mar 7Mar 3Feb 28Feb 24Feb 17
16°FMar 16Mar 10Mar 5Mar 2Feb 27Feb 22Feb 17Feb 12Feb 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 7Oct 10Oct 12Oct 15Oct 18Oct 21Oct 23Oct 28
32°FOct 12Oct 18Oct 21Oct 24Oct 27Oct 29Nov 1Nov 3Nov 8
28°FOct 24Oct 29Nov 1Nov 4Nov 6Nov 10Nov 14Nov 18Nov 25
24°FNov 4Nov 8Nov 12Nov 16Nov 19Nov 24Nov 28Dec 2Dec 8
20°FNov 11Nov 17Nov 22Nov 27Dec 1Dec 4Dec 8Dec 14Dec 20
16°FNov 20Nov 28Dec 3Dec 6Dec 11Dec 15Dec 20Dec 23Dec 28

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°F198190186181177173168163155
32°F222214208204201196191186179
28°F247239233227223218214209202
24°F273263257252246242237230222
20°F295286280274269264257252243
16°F311303297293287282276269260

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
5,012
Cooling degree days, base 65°F
1,243
Growing degree days, base 40°F
6,352
Growing degree days, base 45°F
5,061
Growing degree days, base 50°F
3,910
Growing degree days, base 55°F
2,894
Growing degree days, base 60°F
2,006

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,10003
February89209
March670465
April31015211
May105111475
June4263709
July1356820
August2311775
September55154550
October29828238
November623249
December95308

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 16.5 km from Sullivan. 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 USC00122814 (Farmersburg TV-2). Public domain.