Decherd climate

Decherd Frost Dates and Growing Season

NOAA 1991-2020 normals for Winchester 5SE, 6.9 km from Decherd, elevation 941 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Winchester 5SE. 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 6 and the first fall freeze around October 29, a growing season of about 204 days.

Median at 36°F
last April 21, first October 21
Median at 32°F
last April 6, first October 29
Median at 28°F
last March 26, 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 3Apr 28Apr 24Apr 21Apr 17Apr 13Apr 9Apr 2
32°FApr 25Apr 18Apr 14Apr 10Apr 6Apr 3Mar 31Mar 27Mar 19
28°FApr 10Apr 5Apr 1Mar 30Mar 26Mar 23Mar 18Mar 13Mar 6
24°FApr 1Mar 26Mar 21Mar 16Mar 12Mar 7Mar 4Feb 27Feb 20
20°FMar 21Mar 13Mar 7Mar 3Feb 27Feb 21Feb 15Feb 8Jan 30
16°FMar 8Feb 28Feb 23Feb 15Feb 10Feb 2Jan 28Jan 20Jan 10

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 7Oct 12Oct 15Oct 18Oct 21Oct 23Oct 25Oct 28Nov 1
32°FOct 16Oct 21Oct 24Oct 26Oct 29Oct 31Nov 3Nov 6Nov 11
28°FOct 25Oct 30Nov 1Nov 4Nov 6Nov 9Nov 13Nov 17Nov 24
24°FNov 1Nov 6Nov 10Nov 14Nov 17Nov 23Nov 28Dec 3Dec 9
20°FNov 11Nov 17Nov 24Nov 29Dec 3Dec 7Dec 13Dec 22Jan 1
16°FNov 26Dec 2Dec 9Dec 15Dec 24Dec 30Jan 3Jan 11Jan 21

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°F203196192187182178173169161
32°F226219214209204200196190182
28°F255245239233229224219213205
24°F282272266260255249242236228
20°F317306297290283276270262251
16°F348335328322314306299290280

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
96% 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
3,520
Cooling degree days, base 65°F
1,454
Growing degree days, base 40°F
7,407
Growing degree days, base 45°F
5,902
Growing degree days, base 50°F
4,548
Growing degree days, base 55°F
3,356
Growing degree days, base 60°F
2,327

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January789028
February614040
March4535131
April20932294
May61126531
June3283730
July0391856
August0365829
September22202630
October19345335
November4764102
December700141

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 6.9 km from Decherd. 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 USC00409800 (Winchester 5SE). Public domain.