Wilson County climate

Wilson County Frost Dates and Growing Season

NOAA 1991-2020 normals for Lebanon, 8.4 km from Wilson County, elevation 525 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lebanon. 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 October 28, a growing season of about 206 days.

Median at 36°F
last April 19, first October 19
Median at 32°F
last April 6, first October 28
Median at 28°F
last March 26, 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 5Apr 30Apr 25Apr 22Apr 19Apr 16Apr 13Apr 10Apr 5
32°FApr 23Apr 17Apr 13Apr 10Apr 6Apr 3Mar 31Mar 27Mar 20
28°FApr 10Apr 5Apr 2Mar 30Mar 26Mar 22Mar 17Mar 12Mar 6
24°FApr 1Mar 27Mar 21Mar 16Mar 12Mar 8Mar 3Feb 28Feb 21
20°FMar 20Mar 13Mar 7Mar 2Feb 27Feb 23Feb 18Feb 12Feb 4
16°FMar 8Mar 1Feb 25Feb 18Feb 12Feb 8Feb 3Jan 29Jan 19

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 11Oct 14Oct 17Oct 19Oct 22Oct 24Oct 27Oct 30
32°FOct 15Oct 20Oct 23Oct 26Oct 28Oct 31Nov 1Nov 5Nov 11
28°FOct 24Oct 30Nov 1Nov 4Nov 8Nov 11Nov 15Nov 19Nov 26
24°FNov 3Nov 8Nov 13Nov 16Nov 21Nov 25Nov 30Dec 3Dec 9
20°FNov 14Nov 21Nov 27Dec 1Dec 4Dec 8Dec 14Dec 22Dec 30
16°FNov 29Dec 5Dec 10Dec 19Dec 25Dec 30Jan 3Jan 9Jan 19

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°F202195191186183178174168162
32°F228220214210206201197191185
28°F255246239234228224219213207
24°F279272265260254248242236229
20°F311301293286281276270264254
16°F338329322314308302297289280

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
3,802
Cooling degree days, base 65°F
1,671
Growing degree days, base 40°F
7,451
Growing degree days, base 45°F
5,997
Growing degree days, base 50°F
4,688
Growing degree days, base 55°F
3,529
Growing degree days, base 60°F
2,525

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January849025
February674032
March4977117
April23240288
May67149548
June4332778
July0456921
August0411876
September25223648
October21147322
November495599
December748134

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 8.4 km from Wilson 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 USC00405108 (Lebanon). Public domain.