Wayne County climate

Wayne County Frost Dates and Growing Season

NOAA 1991-2020 normals for Allerton, 5.4 km from Wayne County, elevation 1090 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Allerton. 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 21 and the first fall freeze around October 19, a growing season of about 178 days.

Median at 36°F
last May 2, first October 7
Median at 32°F
last April 21, first October 19
Median at 28°F
last April 11, first October 27

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 17May 12May 7May 5May 2Apr 30Apr 27Apr 23Apr 18
32°FMay 6May 1Apr 27Apr 24Apr 21Apr 18Apr 15Apr 12Apr 7
28°FApr 25Apr 21Apr 17Apr 14Apr 11Apr 8Apr 6Apr 3Mar 30
24°FApr 17Apr 12Apr 8Apr 5Apr 2Mar 31Mar 27Mar 23Mar 16
20°FApr 9Apr 3Mar 31Mar 27Mar 23Mar 19Mar 15Mar 11Mar 7
16°FMar 31Mar 26Mar 21Mar 17Mar 14Mar 11Mar 7Mar 4Feb 28

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 24Sep 29Oct 2Oct 5Oct 7Oct 10Oct 13Oct 16Oct 20
32°FOct 3Oct 7Oct 13Oct 16Oct 19Oct 21Oct 23Oct 26Oct 29
28°FOct 15Oct 19Oct 22Oct 25Oct 27Oct 29Nov 1Nov 3Nov 7
24°FOct 24Oct 29Nov 1Nov 2Nov 4Nov 6Nov 9Nov 12Nov 17
20°FNov 1Nov 4Nov 6Nov 9Nov 12Nov 15Nov 19Nov 22Nov 29
16°FNov 5Nov 10Nov 13Nov 16Nov 20Nov 23Nov 28Dec 1Dec 8

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°F176170165161157153149144138
32°F196190186181178174169165157
28°F215208205201198193190186178
24°F236228222218214211206202194
20°F255247242238233229224219212
16°F273265259253250246241235229

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
6,363
Cooling degree days, base 65°F
874
Growing degree days, base 40°F
5,357
Growing degree days, base 45°F
4,212
Growing degree days, base 50°F
3,188
Growing degree days, base 55°F
2,284
Growing degree days, base 60°F
1,511

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,32800
February1,07502
March824134
April4574118
May18447341
June24175602
July4300761
August8239696
September10293445
October40415166
November792023
December1,16101

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 5.4 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 USC00130149 (Allerton). Public domain.