Stonewall County climate

Stonewall County Frost Dates and Growing Season

NOAA 1991-2020 normals for Aspermont, 3.5 km from Stonewall County, elevation 1670 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Aspermont. 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 29 and the first fall freeze around November 7, a growing season of about 223 days.

Median at 36°F
last April 10, first October 30
Median at 32°F
last March 29, first November 7
Median at 28°F
last March 14, first November 15

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 27Apr 21Apr 17Apr 13Apr 10Apr 6Apr 2Mar 29Mar 22
32°FApr 18Apr 10Apr 5Apr 2Mar 29Mar 26Mar 21Mar 15Mar 8
28°FApr 4Mar 30Mar 24Mar 19Mar 14Mar 10Mar 6Mar 2Feb 24
24°FMar 22Mar 14Mar 9Mar 5Mar 2Feb 27Feb 22Feb 15Feb 8
20°FMar 9Mar 3Feb 28Feb 20Feb 15Feb 10Feb 4Jan 30Jan 19
16°FMar 1Feb 17Feb 10Feb 5Jan 31Jan 26Jan 18Jan 8Dec 28

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 17Oct 22Oct 25Oct 28Oct 30Nov 1Nov 4Nov 7Nov 11
32°FOct 25Oct 30Nov 2Nov 5Nov 7Nov 10Nov 13Nov 17Nov 24
28°FNov 1Nov 5Nov 9Nov 12Nov 15Nov 20Nov 25Nov 30Dec 4
24°FNov 9Nov 15Nov 20Nov 25Nov 28Dec 1Dec 6Dec 10Dec 17
20°FNov 21Nov 28Dec 3Dec 8Dec 13Dec 18Dec 24Jan 1Jan 12
16°FDec 1Dec 12Dec 19Dec 25Jan 1Jan 5Jan 12Jan 22Feb 5

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°F223216210206202198193188182
32°F249239232228223217212206198
28°F272264257251246241235228220
24°F302291283277271266260253245
20°F339327318310303295288279268
16°F365362351342335329321310298

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
99% of years
16°F or colder
83% 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
2,897
Cooling degree days, base 65°F
2,400
Growing degree days, base 40°F
8,865
Growing degree days, base 45°F
7,279
Growing degree days, base 50°F
5,832
Growing degree days, base 55°F
4,532
Growing degree days, base 60°F
3,389

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January687039
February525373
March34621212
April14382403
May31252687
June1460909
July05911,055
August05601,024
September12316755
October120104461
November38811165
December645149

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 3.5 km from Stonewall 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 USC00410394 (Aspermont). Public domain.