Summersville climate

Summersville Frost Dates and Growing Season

NOAA 1991-2020 normals for Summersville 3 Se, 5.1 km from Summersville, elevation 1236 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Summersville 3 Se. 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 7 and the first fall freeze around October 27, a growing season of about 201 days.

Median at 36°F
last April 21, first October 16
Median at 32°F
last April 7, first October 27
Median at 28°F
last March 28, 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 30Apr 25Apr 21Apr 17Apr 14Apr 9Apr 3
32°FApr 27Apr 20Apr 15Apr 10Apr 7Apr 4Mar 31Mar 28Mar 22
28°FApr 13Apr 7Apr 3Mar 31Mar 28Mar 24Mar 20Mar 16Mar 9
24°FApr 3Mar 30Mar 25Mar 20Mar 17Mar 12Mar 8Mar 4Feb 28
20°FMar 24Mar 17Mar 13Mar 8Mar 5Mar 2Feb 28Feb 22Feb 13
16°FMar 13Mar 7Mar 4Mar 1Feb 25Feb 21Feb 16Feb 10Feb 1

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 1Oct 7Oct 11Oct 14Oct 16Oct 19Oct 22Oct 25Oct 29
32°FOct 13Oct 18Oct 22Oct 24Oct 27Oct 30Nov 2Nov 5Nov 10
28°FOct 25Oct 30Nov 1Nov 4Nov 6Nov 9Nov 13Nov 18Nov 24
24°FNov 2Nov 7Nov 11Nov 15Nov 19Nov 23Nov 26Dec 1Dec 5
20°FNov 10Nov 16Nov 22Nov 26Nov 29Dec 3Dec 7Dec 12Dec 20
16°FNov 19Nov 26Dec 1Dec 7Dec 11Dec 17Dec 21Dec 26Jan 3

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°F199191186181177173168163154
32°F225216211205201197193186179
28°F248239234229224219215209201
24°F272263257252247241236229220
20°F294285277273267262257250240
16°F317307301295290284277270259

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
4,512
Cooling degree days, base 65°F
1,279
Growing degree days, base 40°F
6,621
Growing degree days, base 45°F
5,258
Growing degree days, base 50°F
4,043
Growing degree days, base 55°F
2,973
Growing degree days, base 60°F
2,052

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January98909
February776018
March592379
April28521229
May9293467
June8250691
July1388852
August3345807
September52148547
October26329262
November570268
December882013

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 5.1 km from Summersville. 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 USC00238184 (Summersville 3 Se). Public domain.