Terry County climate

Terry County Frost Dates and Growing Season

NOAA 1991-2020 normals for Brownfield #2, 6.5 km from Terry County, elevation 3300 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brownfield #2. 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 3 and the first fall freeze around November 4, a growing season of about 215 days.

Median at 36°F
last April 14, first October 26
Median at 32°F
last April 3, first November 4
Median at 28°F
last March 20, first November 14

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 28Apr 23Apr 20Apr 17Apr 14Apr 10Apr 7Apr 4Mar 31
32°FApr 20Apr 14Apr 9Apr 6Apr 3Apr 1Mar 28Mar 22Mar 16
28°FApr 8Apr 3Mar 31Mar 25Mar 20Mar 15Mar 11Mar 7Mar 1
24°FMar 28Mar 18Mar 13Mar 9Mar 5Mar 1Feb 27Feb 22Feb 16
20°FMar 12Mar 5Mar 1Feb 26Feb 21Feb 17Feb 11Feb 4Jan 27
16°FMar 3Feb 26Feb 18Feb 10Feb 4Jan 30Jan 20Jan 11Jan 1

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 13Oct 18Oct 21Oct 24Oct 26Oct 29Nov 1Nov 4Nov 8
32°FOct 22Oct 26Oct 30Nov 1Nov 4Nov 6Nov 9Nov 13Nov 17
28°FOct 30Nov 4Nov 8Nov 12Nov 14Nov 17Nov 20Nov 23Nov 28
24°FNov 9Nov 14Nov 17Nov 21Nov 24Nov 28Dec 1Dec 5Dec 11
20°FNov 18Nov 24Nov 29Dec 3Dec 6Dec 11Dec 16Dec 22Dec 31
16°FNov 30Dec 6Dec 12Dec 18Dec 23Dec 29Jan 4Jan 13Jan 29

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°F214207203199195191187182177
32°F239230223219215210205200193
28°F262253248242238232226220211
24°F288280273268263258252246237
20°F324313304296290284279271261
16°F361349340331324316309300288

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
93% 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
3,268
Cooling degree days, base 65°F
1,866
Growing degree days, base 40°F
8,010
Growing degree days, base 45°F
6,465
Growing degree days, base 50°F
5,071
Growing degree days, base 55°F
3,841
Growing degree days, base 60°F
2,775

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January747017
February566146
March3898166
April17341337
May45200622
June1401850
July0482947
August0444908
September21229659
October15557384
November4543113
December716023

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 6.5 km from Terry 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 USC00411128 (Brownfield #2). Public domain.