Murfreesboro climate

Murfreesboro Frost Dates and Growing Season

NOAA 1991-2020 normals for Murfreesboro 1W, 2.1 km from Murfreesboro, elevation 460 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Murfreesboro 1W. 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 18, first October 23
Median at 32°F
last April 5, first November 1
Median at 28°F
last March 22, 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°FApr 30Apr 28Apr 24Apr 21Apr 18Apr 15Apr 11Apr 7Apr 2
32°FApr 22Apr 17Apr 12Apr 9Apr 5Apr 2Mar 29Mar 24Mar 16
28°FApr 8Apr 3Mar 30Mar 25Mar 22Mar 18Mar 13Mar 8Mar 1
24°FMar 25Mar 18Mar 14Mar 10Mar 6Mar 2Feb 27Feb 22Feb 14
20°FMar 13Mar 7Mar 2Feb 27Feb 21Feb 14Feb 6Jan 31Jan 23
16°FMar 3Feb 20Feb 13Feb 5Feb 1Jan 27Jan 20Jan 10Dec 31

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 16Oct 19Oct 21Oct 23Oct 26Oct 28Nov 1Nov 4
32°FOct 20Oct 24Oct 27Oct 30Nov 1Nov 3Nov 6Nov 10Nov 15
28°FOct 29Nov 1Nov 5Nov 7Nov 11Nov 14Nov 19Nov 23Dec 1
24°FNov 5Nov 10Nov 14Nov 18Nov 23Nov 27Dec 1Dec 5Dec 12
20°FNov 15Nov 23Nov 29Dec 3Dec 7Dec 15Dec 22Dec 28Jan 5
16°FNov 30Dec 9Dec 20Dec 26Dec 31Jan 3Jan 8Jan 15Jan 28

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°F208201196192188185181176171
32°F234224219214209205201196189
28°F262253246240235230223218209
24°F293283275269263258252245236
20°F329317307300293287280271260
16°F365353344336331323315305294

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
90% 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
3,395
Cooling degree days, base 65°F
1,627
Growing degree days, base 40°F
7,638
Growing degree days, base 45°F
6,118
Growing degree days, base 50°F
4,756
Growing degree days, base 55°F
3,552
Growing degree days, base 60°F
2,508

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January775024
February594037
March4265135
April20626286
May48128546
June2306754
July0436901
August0429894
September16239673
October17351356
November4525113
December703136

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 2.1 km from Murfreesboro. 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 USC00035079 (Murfreesboro 1W). Public domain.