Summit climate

Summit Frost Dates and Growing Season

NOAA 1991-2020 normals for Mccomb/pike Co/john E Lewis AP, 11.3 km from Summit, elevation 413 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mccomb/pike Co/john E Lewis AP. 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 March 11 and the first fall freeze around November 18, a growing season of about 253 days.

Median at 36°F
last March 28, first November 7
Median at 32°F
last March 11, first November 18
Median at 28°F
last February 25, first December 1

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°FApr 17Apr 9Apr 5Apr 1Mar 28Mar 24Mar 19Mar 14Mar 8
32°FApr 2Mar 26Mar 20Mar 15Mar 11Mar 8Mar 2Feb 25Feb 17
28°FMar 18Mar 11Mar 6Mar 1Feb 25Feb 19Feb 13Feb 5Jan 27
24°FMar 5Feb 26Feb 19Feb 11Feb 4Jan 31Jan 25Jan 16Jan 1
20°FFeb 19Feb 9Feb 2Jan 28Jan 22Jan 16Jan 10Jan 3Dec 25
16°FFeb 9Feb 1Jan 27Jan 21Jan 15Jan 10Jan 5Dec 31Dec 22

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 24Oct 30Nov 1Nov 5Nov 7Nov 11Nov 14Nov 19Nov 25
32°FNov 1Nov 6Nov 11Nov 15Nov 18Nov 22Nov 26Dec 1Dec 7
28°FNov 9Nov 17Nov 22Nov 28Dec 1Dec 5Dec 11Dec 20Jan 1
24°FNov 25Dec 2Dec 8Dec 15Dec 23Dec 31Jan 4Jan 11Jan 27
20°FDec 9Dec 19Dec 27Jan 1Jan 5Jan 10Jan 16Jan 24Feb 2
16°FDec 18Dec 27Jan 1Jan 5Jan 9Jan 13Jan 17Jan 23Feb 2

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°F253242235231225219214209200
32°F282273265259253248242235225
28°F318306297289283276269261251
24°F357342334324318310303293281
20°F365365365361350342335328314
16°F365365365365365365365354339

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
93% of years
20°F or colder
64% of years
16°F or colder
27% 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
1,921
Cooling degree days, base 65°F
2,369
Growing degree days, base 40°F
9,627
Growing degree days, base 45°F
7,903
Growing degree days, base 50°F
6,290
Growing degree days, base 55°F
4,822
Growing degree days, base 60°F
3,510

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4996109
February34814155
March21139313
April7994466
May9260716
June0424874
July0498963
August0496961
September2359807
October66143544
November26624242
December44112140

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 11.3 km from Summit. 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 USW00093919 (Mccomb/pike Co/john E Lewis AP). Public domain.