Lexington climate

Lexington Frost Dates and Growing Season

NOAA 1991-2020 normals for Lexington Bluegrass AP, 12.6 km from Lexington, elevation 980 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lexington Bluegrass AP. 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 13 and the first fall freeze around October 28, a growing season of about 196 days.

Median at 36°F
last April 24, first October 19
Median at 32°F
last April 13, first October 28
Median at 28°F
last March 31, 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 11May 6May 1Apr 28Apr 24Apr 21Apr 18Apr 15Apr 10
32°FMay 1Apr 25Apr 20Apr 16Apr 13Apr 9Apr 6Apr 2Mar 30
28°FApr 16Apr 11Apr 5Apr 2Mar 31Mar 28Mar 25Mar 21Mar 15
24°FApr 4Mar 31Mar 26Mar 23Mar 20Mar 16Mar 12Mar 7Feb 28
20°FMar 25Mar 20Mar 16Mar 12Mar 9Mar 4Feb 28Feb 23Feb 15
16°FMar 17Mar 11Mar 6Mar 1Feb 26Feb 21Feb 15Feb 9Feb 2

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 13Oct 16Oct 19Oct 21Oct 24Oct 26Oct 30
32°FOct 16Oct 20Oct 23Oct 25Oct 28Oct 30Nov 1Nov 4Nov 8
28°FOct 25Oct 31Nov 1Nov 4Nov 6Nov 9Nov 12Nov 17Nov 22
24°FNov 4Nov 7Nov 10Nov 14Nov 17Nov 20Nov 24Nov 29Dec 5
20°FNov 10Nov 17Nov 21Nov 26Nov 30Dec 2Dec 6Dec 13Dec 22
16°FNov 21Nov 29Dec 3Dec 7Dec 12Dec 19Dec 24Dec 28Jan 6

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°F195189184181177173168163156
32°F217209205200196192188182175
28°F241233228224220216212207199
24°F267258252247242238233228221
20°F295286278272268262256248241
16°F320310304297292285279273263

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
4,432
Cooling degree days, base 65°F
1,289
Growing degree days, base 40°F
6,689
Growing degree days, base 45°F
5,319
Growing degree days, base 50°F
4,093
Growing degree days, base 55°F
3,015
Growing degree days, base 60°F
2,079

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January966014
February769021
March594482
April28723235
May96109480
June8257699
July0363828
August1333797
September42166575
October25633272
November569271
December845020

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 12.6 km from Lexington. 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 USW00093820 (Lexington Bluegrass AP). Public domain.