Fall Branch climate

Fall Branch Frost Dates and Growing Season

NOAA 1991-2020 normals for Kingsport, 14.2 km from Fall Branch, elevation 1284 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Kingsport. 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 9 and the first fall freeze around October 29, a growing season of about 203 days.

Median at 36°F
last April 23, first October 20
Median at 32°F
last April 9, first October 29
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 10May 5Apr 30Apr 26Apr 23Apr 20Apr 16Apr 12Apr 6
32°FApr 25Apr 20Apr 16Apr 13Apr 9Apr 6Apr 2Mar 30Mar 25
28°FApr 12Apr 6Apr 2Mar 31Mar 28Mar 25Mar 21Mar 17Mar 10
24°FMar 31Mar 27Mar 23Mar 19Mar 15Mar 11Mar 7Mar 3Feb 25
20°FMar 21Mar 15Mar 9Mar 5Mar 1Feb 26Feb 21Feb 13Feb 3
16°FMar 11Mar 4Feb 28Feb 22Feb 14Feb 7Feb 1Jan 26Jan 15

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 6Oct 11Oct 14Oct 17Oct 20Oct 22Oct 26Oct 28Nov 1
32°FOct 15Oct 20Oct 24Oct 26Oct 29Nov 1Nov 2Nov 5Nov 10
28°FOct 25Oct 30Nov 1Nov 4Nov 6Nov 9Nov 13Nov 16Nov 23
24°FNov 4Nov 8Nov 12Nov 15Nov 18Nov 22Nov 26Dec 1Dec 7
20°FNov 13Nov 19Nov 25Nov 30Dec 3Dec 7Dec 13Dec 21Dec 29
16°FNov 27Dec 4Dec 9Dec 14Dec 22Dec 27Jan 1Jan 7Jan 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°F201194189185180177172167158
32°F223215210207203199194189181
28°F247240234229224220216210202
24°F276266259254250246240234226
20°F308299290284277272265258248
16°F339329321314306300293284272

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
98% 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
3,976
Cooling degree days, base 65°F
1,257
Growing degree days, base 40°F
6,866
Growing degree days, base 45°F
5,428
Growing degree days, base 50°F
4,152
Growing degree days, base 55°F
3,035
Growing degree days, base 60°F
2,070

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January873014
February693020
March524291
April24220255
May74105498
June6253697
July0357822
August0324789
September27169593
October22825283
November531171
December778020

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 14.2 km from Fall Branch. 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 USC00404858 (Kingsport). Public domain.