Graves County climate

Graves County Frost Dates and Growing Season

NOAA 1991-2020 normals for Murray, 33 km from Graves County, elevation 527 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Murray. 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 5 and the first fall freeze around November 1, a growing season of about 209 days.

Median at 36°F
last April 16, first October 23
Median at 32°F
last April 5, first November 1
Median at 28°F
last March 24, first November 11

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

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 12Oct 15Oct 18Oct 21Oct 23Oct 25Oct 27Oct 30Nov 2
32°FOct 20Oct 24Oct 27Oct 29Nov 1Nov 3Nov 5Nov 10Nov 14
28°FOct 30Nov 2Nov 5Nov 8Nov 11Nov 14Nov 18Nov 22Nov 29
24°FNov 7Nov 11Nov 15Nov 19Nov 22Nov 26Dec 1Dec 3Dec 10
20°FNov 16Nov 22Nov 27Nov 30Dec 3Dec 7Dec 12Dec 19Dec 28
16°FNov 28Dec 2Dec 9Dec 14Dec 21Dec 26Jan 1Jan 7Jan 14

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°F206200196192188184180175169
32°F230222217213209204200196188
28°F256248242236232228223218210
24°F283272266261256251247240232
20°F309299291285280274268263254
16°F336327319312306300294285275

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
3,861
Cooling degree days, base 65°F
1,638
Growing degree days, base 40°F
7,410
Growing degree days, base 45°F
5,969
Growing degree days, base 50°F
4,670
Growing degree days, base 55°F
3,514
Growing degree days, base 60°F
2,503

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January883018
February685133
March4918122
April20842308
May56148557
June3328775
July0439904
August0406871
September24217644
October20746322
November514492
December789026

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 33 km from Graves 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 USC00155694 (Murray). Public domain.