Wayne County climate

Wayne County Frost Dates and Growing Season

NOAA 1991-2020 normals for Waynesboro, 7.6 km from Wayne County, elevation 750 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Waynesboro. 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 14 and the first fall freeze around October 24, a growing season of about 192 days.

Median at 36°F
last April 26, first October 15
Median at 32°F
last April 14, first October 24
Median at 28°F
last April 2, 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 11May 5May 1Apr 29Apr 26Apr 23Apr 20Apr 16Apr 10
32°FApr 30Apr 25Apr 20Apr 17Apr 14Apr 10Apr 7Apr 2Mar 28
28°FApr 19Apr 13Apr 8Apr 5Apr 2Mar 31Mar 25Mar 19Mar 14
24°FApr 7Apr 2Mar 28Mar 23Mar 19Mar 15Mar 10Mar 3Feb 25
20°FMar 26Mar 18Mar 14Mar 9Mar 4Feb 28Feb 24Feb 18Feb 8
16°FMar 14Mar 5Feb 28Feb 24Feb 18Feb 12Feb 4Jan 30Jan 19

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 6Oct 10Oct 12Oct 15Oct 18Oct 21Oct 25Oct 28
32°FOct 12Oct 16Oct 19Oct 22Oct 24Oct 27Oct 30Nov 1Nov 7
28°FOct 21Oct 26Oct 29Nov 1Nov 3Nov 5Nov 8Nov 12Nov 17
24°FNov 1Nov 4Nov 7Nov 11Nov 14Nov 17Nov 21Nov 26Dec 1
20°FNov 9Nov 14Nov 18Nov 22Nov 27Dec 1Dec 4Dec 10Dec 22
16°FNov 17Nov 26Dec 1Dec 5Dec 10Dec 19Dec 26Jan 2Jan 12

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°F192185179176173169165160152
32°F213207201196192189185180173
28°F238229223218214210205200193
24°F266257249244239233227222215
20°F301288279273267261256249239
16°F336323314306300293285277265

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
99% 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
3,876
Cooling degree days, base 65°F
1,341
Growing degree days, base 40°F
7,031
Growing degree days, base 45°F
5,579
Growing degree days, base 50°F
4,279
Growing degree days, base 55°F
3,141
Growing degree days, base 60°F
2,161

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January843022
February665030
March5043103
April24524260
May78104493
June5266711
July0377842
August1347811
September32181599
October22135300
November523282
December758028

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 7.6 km from Wayne 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 USC00409502 (Waynesboro). Public domain.