Fentress County climate

Fentress County Frost Dates and Growing Season

NOAA 1991-2020 normals for Jamestown, 5.1 km from Fentress County, elevation 1690 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Jamestown. 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 20 and the first fall freeze around October 22, a growing season of about 183 days.

Median at 36°F
last May 2, first October 14
Median at 32°F
last April 20, first October 22
Median at 28°F
last April 6, first October 31

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 8May 5May 2Apr 29Apr 24Apr 21Apr 16
32°FMay 8May 2Apr 28Apr 23Apr 20Apr 17Apr 14Apr 11Apr 6
28°FApr 25Apr 17Apr 13Apr 10Apr 6Apr 4Apr 1Mar 28Mar 21
24°FApr 10Apr 4Apr 1Mar 29Mar 25Mar 20Mar 15Mar 10Mar 3
20°FMar 30Mar 24Mar 19Mar 14Mar 9Mar 5Mar 1Feb 25Feb 16
16°FMar 19Mar 12Mar 6Mar 2Feb 27Feb 22Feb 15Feb 8Feb 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 2Oct 6Oct 9Oct 11Oct 14Oct 16Oct 19Oct 22Oct 26
32°FOct 10Oct 14Oct 17Oct 19Oct 22Oct 24Oct 26Oct 30Nov 3
28°FOct 18Oct 22Oct 25Oct 28Oct 31Nov 1Nov 4Nov 8Nov 14
24°FOct 28Nov 1Nov 4Nov 8Nov 10Nov 14Nov 18Nov 23Nov 30
20°FNov 8Nov 13Nov 17Nov 21Nov 25Nov 29Dec 3Dec 7Dec 16
16°FNov 17Nov 24Nov 30Dec 3Dec 7Dec 13Dec 19Dec 26Jan 1

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°F183176171167163160156152146
32°F203196191187183179175170163
28°F229220214210205201197190182
24°F260250243237232228223217210
20°F286277269263257251246240233
16°F318305298291285279272264253

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
4,486
Cooling degree days, base 65°F
960
Growing degree days, base 40°F
6,266
Growing degree days, base 45°F
4,885
Growing degree days, base 50°F
3,666
Growing degree days, base 55°F
2,615
Growing degree days, base 60°F
1,709

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January937013
February758019
March591275
April31814203
May11572429
June9192633
July1283747
August2267730
September54114511
October28716231
November581153
December832022

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 Fentress 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 USC00404590 (Jamestown). Public domain.