Campbell climate

Campbell Frost Dates and Growing Season

NOAA 1991-2020 normals for Greenville Kgvl Radio, 13.9 km from Campbell, elevation 545 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Greenville Kgvl Radio. 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 18 and the first fall freeze around November 16, a growing season of about 244 days.

Median at 36°F
last April 1, first November 5
Median at 32°F
last March 18, first November 16
Median at 28°F
last March 4, 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 23Apr 15Apr 9Apr 4Apr 1Mar 29Mar 23Mar 19Mar 13
32°FApr 6Mar 31Mar 26Mar 21Mar 18Mar 14Mar 9Mar 5Feb 27
28°FMar 23Mar 16Mar 12Mar 8Mar 4Mar 1Feb 25Feb 18Feb 10
24°FMar 13Mar 6Mar 2Feb 25Feb 18Feb 11Feb 5Jan 29Jan 19
20°FMar 3Feb 24Feb 14Feb 6Jan 31Jan 27Jan 21Jan 12Dec 31
16°FFeb 20Feb 8Feb 2Jan 29Jan 21Jan 15Jan 8Jan 1Dec 21

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 27Oct 31Nov 3Nov 5Nov 8Nov 12Nov 16Nov 22
32°FNov 1Nov 5Nov 8Nov 12Nov 16Nov 19Nov 24Nov 29Dec 5
28°FNov 7Nov 13Nov 19Nov 24Nov 28Dec 1Dec 5Dec 10Dec 18
24°FNov 19Nov 27Dec 1Dec 7Dec 12Dec 18Dec 25Jan 2Jan 12
20°FDec 1Dec 10Dec 17Dec 24Jan 1Jan 4Jan 12Jan 21Feb 2
16°FDec 12Dec 19Dec 28Jan 1Jan 5Jan 11Jan 19Jan 29Feb 7

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°F245237230224218214208201192
32°F268260255250244240234226215
28°F298286279274269263258251243
24°F334324315305298292283275264
20°F365356345337332324314303291
16°F365365365365360351342334319

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
99% of years
20°F or colder
86% of years
16°F or colder
56% 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
2,365
Cooling degree days, base 65°F
2,755
Growing degree days, base 40°F
9,636
Growing degree days, base 45°F
7,977
Growing degree days, base 50°F
6,444
Growing degree days, base 55°F
5,060
Growing degree days, base 60°F
3,828

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January605364
February4416104
March28226252
April9893448
May14270721
June0492942
July06391,104
August06451,110
September4407853
October76149541
November29824224
December546482

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 13.9 km from Campbell. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00413734 (Greenville Kgvl Radio). Public domain.