Campbell County climate

Campbell County Frost Dates and Growing Season

NOAA 1991-2020 normals for Pollock, 23.5 km from Campbell County, elevation 1639 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pollock. 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 May 8 and the first fall freeze around September 30, a growing season of about 143 days.

Median at 36°F
last May 18, first September 22
Median at 32°F
last May 8, first September 30
Median at 28°F
last April 30, first October 8

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 31May 26May 23May 20May 18May 15May 12May 10May 5
32°FMay 21May 17May 13May 10May 8May 6May 3May 1Apr 27
28°FMay 12May 7May 4May 2Apr 30Apr 27Apr 23Apr 19Apr 15
24°FMay 3Apr 29Apr 25Apr 22Apr 18Apr 16Apr 13Apr 10Apr 6
20°FApr 24Apr 19Apr 16Apr 13Apr 11Apr 8Apr 5Apr 2Mar 29
16°FApr 16Apr 12Apr 8Apr 5Apr 3Mar 31Mar 29Mar 23Mar 16

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 10Sep 14Sep 17Sep 20Sep 22Sep 24Sep 27Sep 30Oct 3
32°FSep 18Sep 22Sep 25Sep 27Sep 30Oct 2Oct 4Oct 7Oct 11
28°FSep 25Sep 30Oct 2Oct 5Oct 8Oct 11Oct 14Oct 18Oct 22
24°FOct 2Oct 7Oct 12Oct 15Oct 18Oct 21Oct 23Oct 27Oct 31
20°FOct 11Oct 16Oct 20Oct 23Oct 26Oct 29Nov 1Nov 4Nov 9
16°FOct 20Oct 24Oct 29Nov 1Nov 4Nov 6Nov 9Nov 13Nov 18

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°F144138133130127123120115109
32°F160154150146143139136131125
28°F180173168163160156152148141
24°F198192187182178174170164157
20°F216208204200196192188182173
16°F233227221217212209204199192

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
8,144
Cooling degree days, base 65°F
638
Growing degree days, base 40°F
4,472
Growing degree days, base 45°F
3,472
Growing degree days, base 50°F
2,581
Growing degree days, base 55°F
1,810
Growing degree days, base 60°F
1,159

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,59500
February1,30900
March1,06705
April611252
May27322246
June57109503
July10244699
August21202646
September16358356
October581373
November1,02202
December1,43800

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 23.5 km from Campbell 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 USC00396712 (Pollock). Public domain.