Cumby climate

Cumby Frost Dates and Growing Season

NOAA 1991-2020 normals for Sulphur Springs, 19.8 km from Cumby, elevation 495 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sulphur Springs. 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 15 and the first fall freeze around November 14, a growing season of about 245 days.

Median at 36°F
last March 31, first November 4
Median at 32°F
last March 15, first November 14
Median at 28°F
last March 2, first November 28

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 17Apr 10Apr 6Apr 3Mar 31Mar 26Mar 21Mar 17Mar 11
32°FApr 4Mar 29Mar 23Mar 18Mar 15Mar 11Mar 6Mar 2Feb 25
28°FMar 19Mar 14Mar 9Mar 5Mar 2Feb 27Feb 22Feb 16Feb 7
24°FMar 10Mar 4Feb 28Feb 22Feb 16Feb 10Feb 3Jan 28Jan 16
20°FMar 2Feb 19Feb 11Feb 3Jan 29Jan 22Jan 16Jan 6Dec 26
16°FFeb 16Feb 6Jan 29Jan 22Jan 18Jan 11Jan 5Dec 29Dec 19

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 22Oct 26Oct 30Nov 1Nov 4Nov 7Nov 11Nov 15Nov 21
32°FOct 29Nov 3Nov 7Nov 11Nov 14Nov 18Nov 23Nov 27Dec 3
28°FNov 7Nov 13Nov 18Nov 23Nov 28Dec 1Dec 5Dec 10Dec 18
24°FNov 17Nov 26Dec 1Dec 6Dec 12Dec 18Dec 26Jan 2Jan 14
20°FDec 4Dec 11Dec 18Dec 25Dec 31Jan 5Jan 13Jan 19Feb 3
16°FDec 9Dec 17Dec 23Dec 30Jan 3Jan 10Jan 16Jan 23Feb 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°F243235229225219214209203195
32°F271263256251245241235227217
28°F301291284279272266261253245
24°F335324315307300294289280267
20°F365363352343336330323311299
16°F365365365365365358348339327

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
98% of years
20°F or colder
81% of years
16°F or colder
45% 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
2,514
Cooling degree days, base 65°F
2,517
Growing degree days, base 40°F
9,280
Growing degree days, base 45°F
7,646
Growing degree days, base 50°F
6,139
Growing degree days, base 55°F
4,776
Growing degree days, base 60°F
3,566

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January634259
February463596
March30024241
April11776416
May18244691
June0456906
July05911,055
August05891,054
September5375820
October90129508
November31622214
December571479

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 19.8 km from Cumby. 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 USC00418743 (Sulphur Springs). Public domain.