Waldron climate

Waldron Frost Dates and Growing Season

NOAA 1991-2020 normals for Shelbyville Sewage Plt, 13.5 km from Waldron, elevation 752 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Shelbyville Sewage Plt. 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 17 and the first fall freeze around October 22, a growing season of about 187 days.

Median at 36°F
last April 28, first October 12
Median at 32°F
last April 17, first October 22
Median at 28°F
last April 5, first November 1

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 14May 8May 4May 1Apr 28Apr 25Apr 22Apr 20Apr 14
32°FMay 3Apr 28Apr 23Apr 20Apr 17Apr 14Apr 11Apr 7Apr 3
28°FApr 22Apr 16Apr 12Apr 8Apr 5Apr 2Mar 31Mar 28Mar 22
24°FApr 8Apr 3Mar 31Mar 29Mar 25Mar 22Mar 19Mar 15Mar 9
20°FMar 30Mar 25Mar 21Mar 18Mar 14Mar 11Mar 8Mar 4Feb 26
16°FMar 21Mar 16Mar 13Mar 9Mar 5Mar 2Feb 26Feb 20Feb 12

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°FSep 29Oct 3Oct 7Oct 10Oct 12Oct 14Oct 17Oct 20Oct 25
32°FOct 9Oct 13Oct 17Oct 19Oct 22Oct 24Oct 27Oct 30Nov 4
28°FOct 19Oct 24Oct 27Oct 30Nov 1Nov 4Nov 7Nov 12Nov 17
24°FOct 30Nov 1Nov 5Nov 9Nov 13Nov 17Nov 21Nov 26Dec 3
20°FNov 6Nov 13Nov 18Nov 22Nov 26Dec 1Dec 4Dec 8Dec 15
16°FNov 16Nov 24Nov 29Dec 3Dec 7Dec 12Dec 17Dec 22Dec 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°F184177173169165161157152146
32°F206200196191187183178173167
28°F231223218214210206202195189
24°F256247241237232228223218211
20°F281272266260255250244239232
16°F305295289284278273267262252

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
5,436
Cooling degree days, base 65°F
989
Growing degree days, base 40°F
5,833
Growing degree days, base 45°F
4,596
Growing degree days, base 50°F
3,497
Growing degree days, base 55°F
2,526
Growing degree days, base 60°F
1,688

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,14703
February94106
March744243
April38410160
May13980413
June17217651
July2293756
August5248708
September68119502
October33118205
November665143
December99406

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 13.5 km from Waldron. 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 USC00127999 (Shelbyville Sewage Plt). Public domain.