Flatwoods climate

Flatwoods Frost Dates and Growing Season

NOAA 1991-2020 normals for S Pt, 15.4 km from Flatwoods, elevation 553 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for S Pt. 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 16 and the first fall freeze around October 30, a growing season of about 196 days.

Median at 36°F
last April 28, first October 20
Median at 32°F
last April 16, first October 30
Median at 28°F
last April 2, first November 8

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 13May 8May 4Apr 30Apr 28Apr 24Apr 21Apr 18Apr 13
32°FMay 4Apr 28Apr 22Apr 19Apr 16Apr 13Apr 10Apr 7Apr 2
28°FApr 19Apr 13Apr 8Apr 5Apr 2Mar 31Mar 28Mar 24Mar 18
24°FApr 4Mar 31Mar 28Mar 24Mar 21Mar 17Mar 13Mar 8Mar 1
20°FMar 25Mar 19Mar 15Mar 12Mar 8Mar 3Feb 28Feb 24Feb 15
16°FMar 15Mar 9Mar 5Feb 28Feb 24Feb 19Feb 11Feb 5Jan 31

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 7Oct 12Oct 15Oct 17Oct 20Oct 22Oct 25Oct 28Nov 1
32°FOct 18Oct 22Oct 25Oct 27Oct 30Nov 1Nov 3Nov 5Nov 10
28°FOct 29Nov 1Nov 3Nov 5Nov 8Nov 11Nov 13Nov 16Nov 21
24°FNov 5Nov 9Nov 12Nov 15Nov 17Nov 21Nov 26Dec 1Dec 7
20°FNov 12Nov 18Nov 23Nov 28Dec 1Dec 5Dec 10Dec 18Dec 25
16°FNov 27Dec 3Dec 9Dec 15Dec 20Dec 25Dec 29Jan 3Jan 12

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°F192186181177174170166161155
32°F215208204200196192188182176
28°F241232227223219215211206199
24°F268259252248243238233229222
20°F298287281275269264258252244
16°F327316308302296290283276267

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
4,604
Cooling degree days, base 65°F
1,232
Growing degree days, base 40°F
6,481
Growing degree days, base 45°F
5,133
Growing degree days, base 50°F
3,938
Growing degree days, base 55°F
2,894
Growing degree days, base 60°F
1,990

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January975011
February802012
March635366
April31519212
May11499454
June14254690
July1354818
August3319781
September47158562
October27126254
November581162
December847016

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 15.4 km from Flatwoods. 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 USC00337857 (S Pt). Public domain.