Lamar climate

Lamar Frost Dates and Growing Season

NOAA 1991-2020 normals for Clarksville 2N, 10.1 km from Lamar, elevation 448 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Clarksville 2N. 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 March 24 and the first fall freeze around November 10, a growing season of about 233 days.

Median at 36°F
last April 6, first October 31
Median at 32°F
last March 24, first November 10
Median at 28°F
last March 9, first November 24

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

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°F230221216212207203199193186
32°F258249242237233228223218211
28°F284275269264259253247242234
24°F310301294287282277270264255
20°F345334325318310305299291280
16°F365360351344338331325315302

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
97% of years
16°F or colder
84% 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
3,428
Cooling degree days, base 65°F
1,917
Growing degree days, base 40°F
7,955
Growing degree days, base 45°F
6,444
Growing degree days, base 50°F
5,085
Growing degree days, base 55°F
3,879
Growing degree days, base 60°F
2,822

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January814121
February614138
March4339139
April18739317
May42158582
June1365814
July0508973
August0493958
September13274711
October15265387
November4415116
December730030

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 10.1 km from Lamar. 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 USC00031459 (Clarksville 2N). Public domain.