Greene County climate

Greene County Frost Dates and Growing Season

NOAA 1991-2020 normals for Xenia 6 Sse, 9.9 km from Greene County, elevation 997 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Xenia 6 Sse. 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 18 and the first fall freeze around October 24, a growing season of about 188 days.

Median at 36°F
last April 28, first October 12
Median at 32°F
last April 18, first October 24
Median at 28°F
last April 5, first November 3

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 14May 8May 4Apr 30Apr 28Apr 24Apr 21Apr 18Apr 14
32°FMay 4Apr 29Apr 24Apr 21Apr 18Apr 15Apr 11Apr 7Apr 3
28°FApr 20Apr 16Apr 12Apr 8Apr 5Apr 3Mar 31Mar 28Mar 23
24°FApr 11Apr 5Apr 2Mar 31Mar 27Mar 24Mar 21Mar 16Mar 10
20°FApr 1Mar 28Mar 24Mar 20Mar 17Mar 13Mar 10Mar 5Feb 26
16°FMar 23Mar 18Mar 13Mar 10Mar 6Mar 2Feb 28Feb 21Feb 13

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 29Oct 4Oct 7Oct 9Oct 12Oct 15Oct 18Oct 21Oct 25
32°FOct 11Oct 15Oct 19Oct 22Oct 24Oct 26Oct 29Nov 1Nov 5
28°FOct 21Oct 25Oct 29Nov 1Nov 3Nov 6Nov 10Nov 15Nov 20
24°FOct 31Nov 4Nov 8Nov 12Nov 16Nov 20Nov 25Nov 30Dec 6
20°FNov 9Nov 15Nov 21Nov 26Nov 30Dec 2Dec 6Dec 12Dec 19
16°FNov 18Nov 26Dec 1Dec 5Dec 9Dec 14Dec 20Dec 25Dec 31

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°F187180175170167163159153147
32°F207201197193188185179174167
28°F235226220216212208203198191
24°F259250244238234229224218212
20°F282273267262257252247240233
16°F305298290284279273268262254

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
5,064
Cooling degree days, base 65°F
967
Growing degree days, base 40°F
6,013
Growing degree days, base 45°F
4,725
Growing degree days, base 50°F
3,573
Growing degree days, base 55°F
2,557
Growing degree days, base 60°F
1,687

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,08007
February884010
March692260
April34217193
May12984425
June17209642
July1283747
August5236696
September67115499
October30321225
November613158
December932011

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 9.9 km from Greene 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 USC00339361 (Xenia 6 Sse). Public domain.