Nelsonville climate

Nelsonville Frost Dates and Growing Season

NOAA 1991-2020 normals for Athens Ou, 19 km from Nelsonville, elevation 684 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Athens Ou. 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 25 and the first fall freeze around October 23, a growing season of about 179 days.

Median at 36°F
last May 5, first October 11
Median at 32°F
last April 25, first October 23
Median at 28°F
last April 11, first November 1

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 21May 15May 11May 8May 5May 1Apr 28Apr 24Apr 20
32°FMay 12May 6May 1Apr 28Apr 25Apr 22Apr 19Apr 16Apr 11
28°FApr 30Apr 23Apr 19Apr 14Apr 11Apr 8Apr 5Apr 2Mar 28
24°FApr 14Apr 9Apr 5Apr 3Mar 31Mar 29Mar 25Mar 21Mar 14
20°FApr 3Mar 30Mar 26Mar 23Mar 19Mar 16Mar 12Mar 7Feb 28
16°FMar 26Mar 20Mar 17Mar 12Mar 8Mar 5Mar 1Feb 24Feb 15

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 26Oct 1Oct 5Oct 8Oct 11Oct 13Oct 16Oct 19Oct 24
32°FOct 8Oct 13Oct 16Oct 20Oct 23Oct 25Oct 28Oct 31Nov 3
28°FOct 18Oct 23Oct 27Oct 30Nov 1Nov 2Nov 4Nov 8Nov 13
24°FOct 30Nov 1Nov 4Nov 7Nov 10Nov 13Nov 15Nov 18Nov 25
20°FNov 6Nov 11Nov 14Nov 17Nov 21Nov 25Nov 29Dec 3Dec 10
16°FNov 15Nov 21Nov 26Dec 1Dec 4Dec 9Dec 15Dec 21Dec 29

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°F176170166162158154149144135
32°F198192186183179174169164157
28°F221214210205202197193188181
24°F245238233228224220216212206
20°F273263256251245240236231224
16°F300290283276270264258252244

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
5,386
Cooling degree days, base 65°F
767
Growing degree days, base 40°F
5,543
Growing degree days, base 45°F
4,295
Growing degree days, base 50°F
3,198
Growing degree days, base 55°F
2,239
Growing degree days, base 60°F
1,422

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,09308
February90209
March741246
April38711162
May16950353
June28158580
July3241704
August7207665
September8585452
October36114177
November671033
December94109

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 19 km from Nelsonville. 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 USC00330279 (Athens Ou). Public domain.