Wolfe County climate

Wolfe County Frost Dates and Growing Season

NOAA 1991-2020 normals for Jackson, 22.9 km from Wolfe County, elevation 1364 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Jackson. 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 November 1, a growing season of about 208 days.

Median at 36°F
last April 18, first October 22
Median at 32°F
last April 6, first November 1
Median at 28°F
last March 27, first November 12

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 2Apr 27Apr 22Apr 18Apr 15Apr 12Apr 8Apr 4
32°FApr 25Apr 18Apr 13Apr 9Apr 6Apr 3Mar 31Mar 27Mar 21
28°FApr 11Apr 5Apr 2Mar 31Mar 27Mar 23Mar 19Mar 16Mar 10
24°FApr 2Mar 28Mar 23Mar 19Mar 16Mar 12Mar 7Mar 2Feb 25
20°FMar 22Mar 17Mar 12Mar 8Mar 4Feb 28Feb 24Feb 18Feb 8
16°FMar 14Mar 7Mar 2Feb 27Feb 22Feb 15Feb 9Feb 3Jan 27

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 9Oct 14Oct 17Oct 20Oct 22Oct 24Oct 27Oct 30Nov 4
32°FOct 18Oct 23Oct 26Oct 30Nov 1Nov 4Nov 7Nov 11Nov 17
28°FNov 1Nov 3Nov 6Nov 9Nov 12Nov 15Nov 20Nov 25Dec 1
24°FNov 8Nov 13Nov 16Nov 20Nov 25Nov 29Dec 3Dec 8Dec 16
20°FNov 16Nov 23Nov 28Dec 2Dec 7Dec 12Dec 18Dec 24Dec 29
16°FNov 29Dec 5Dec 11Dec 18Dec 24Dec 28Jan 1Jan 8Jan 16

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°F205199194191186182177171164
32°F230222216212208204199193185
28°F258248242236231227222217209
24°F282271265260254250245238230
20°F308297291284278273266259250
16°F332323314308302296289283272

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
4,069
Cooling degree days, base 65°F
1,236
Growing degree days, base 40°F
6,884
Growing degree days, base 45°F
5,461
Growing degree days, base 50°F
4,179
Growing degree days, base 55°F
3,046
Growing degree days, base 60°F
2,064

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January905020
February711132
March5418113
April24441286
May89109487
June9235676
July0334798
August1306770
September39161572
October23336294
November511499
December785031

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 22.9 km from Wolfe 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 USW00003889 (Jackson). Public domain.