Lexington climate

Lexington Frost Dates and Growing Season

NOAA 1991-2020 normals for Norman 3SSE, 20.6 km from Lexington, elevation 1128 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Norman 3SSE. 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 3 and the first fall freeze around November 3, a growing season of about 212 days.

Median at 36°F
last April 14, first October 25
Median at 32°F
last April 3, first November 3
Median at 28°F
last March 23, first November 12

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°FApr 28Apr 23Apr 20Apr 17Apr 14Apr 10Apr 7Apr 4Mar 30
32°FApr 18Apr 14Apr 9Apr 6Apr 3Mar 31Mar 29Mar 25Mar 19
28°FApr 7Apr 3Mar 31Mar 28Mar 23Mar 20Mar 16Mar 12Mar 5
24°FMar 29Mar 23Mar 18Mar 14Mar 11Mar 9Mar 5Mar 1Feb 24
20°FMar 19Mar 13Mar 9Mar 5Mar 2Feb 27Feb 22Feb 17Feb 8
16°FMar 10Mar 4Mar 1Feb 23Feb 17Feb 11Feb 6Jan 30Jan 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 11Oct 17Oct 20Oct 22Oct 25Oct 28Oct 31Nov 2Nov 6
32°FOct 21Oct 25Oct 29Nov 1Nov 3Nov 6Nov 9Nov 12Nov 17
28°FOct 27Nov 1Nov 5Nov 8Nov 12Nov 15Nov 17Nov 21Nov 27
24°FNov 4Nov 10Nov 14Nov 18Nov 21Nov 25Nov 29Dec 3Dec 9
20°FNov 13Nov 20Nov 25Nov 29Dec 2Dec 6Dec 11Dec 17Dec 25
16°FNov 26Dec 2Dec 7Dec 13Dec 19Dec 25Dec 31Jan 5Jan 15

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°F212205200196193189184180173
32°F234226221216212209204198191
28°F256248242237232228224219211
24°F280271266260254250245240231
20°F306297290283277271267261252
16°F334325316309304298291282273

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
99% 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
3,479
Cooling degree days, base 65°F
1,945
Growing degree days, base 40°F
7,971
Growing degree days, base 45°F
6,467
Growing degree days, base 50°F
5,109
Growing degree days, base 55°F
3,902
Growing degree days, base 60°F
2,849

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January812018
February621147
March4289152
April19842316
May48160577
June1368817
July0522987
August0501965
September18264696
October16471385
November4476123
December741025

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 20.6 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 USC00346386 (Norman 3SSE). Public domain.