Lee climate

Lee Frost Dates and Growing Season

NOAA 1991-2020 normals for Lenox Dale, 3.5 km from Lee, elevation 1004 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lenox Dale. 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 May 7 and the first fall freeze around October 3, a growing season of about 147 days.

Median at 36°F
last May 20, first September 24
Median at 32°F
last May 7, first October 3
Median at 28°F
last April 27, first October 15

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°FJun 3May 30May 26May 23May 20May 17May 14May 11May 6
32°FMay 21May 17May 13May 10May 7May 5May 2Apr 30Apr 26
28°FMay 11May 6May 3Apr 30Apr 27Apr 24Apr 22Apr 18Apr 13
24°FApr 29Apr 23Apr 20Apr 17Apr 13Apr 11Apr 8Apr 5Apr 2
20°FApr 15Apr 10Apr 7Apr 4Apr 3Apr 1Mar 30Mar 25Mar 19
16°FApr 5Apr 2Mar 31Mar 29Mar 26Mar 23Mar 19Mar 16Mar 11

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°FSep 11Sep 15Sep 19Sep 22Sep 24Sep 27Sep 30Oct 2Oct 7
32°FSep 21Sep 25Sep 29Oct 1Oct 3Oct 6Oct 9Oct 14Oct 18
28°FOct 1Oct 4Oct 7Oct 11Oct 15Oct 19Oct 23Oct 28Nov 1
24°FOct 10Oct 16Oct 21Oct 25Oct 29Nov 1Nov 3Nov 6Nov 12
20°FOct 24Oct 31Nov 2Nov 5Nov 8Nov 12Nov 15Nov 19Nov 24
16°FNov 5Nov 11Nov 14Nov 18Nov 21Nov 24Nov 28Dec 1Dec 8

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°F144139134130126122118113107
32°F164158154151147143139134128
28°F191184179174170166161156150
24°F215209203199195190186180172
20°F241232227223219216211206198
16°F263256251246242237232227221

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
7,246
Cooling degree days, base 65°F
405
Growing degree days, base 40°F
4,181
Growing degree days, base 45°F
3,149
Growing degree days, base 50°F
2,253
Growing degree days, base 55°F
1,491
Growing degree days, base 60°F
867

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,32800
February1,13500
March1,01405
April632243
May30119215
June8873436
July18156603
August30120555
September18734307
October526278
November833010
December1,15501

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 3.5 km from Lee. 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 USC00194131 (Lenox Dale). Public domain.