Caswell County climate

Caswell County Frost Dates and Growing Season

NOAA 1991-2020 normals for Yanceyville 4 Se, 7.3 km from Caswell County, elevation 635 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Yanceyville 4 Se. 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 31 and the first fall freeze around November 4, a growing season of about 218 days.

Median at 36°F
last April 13, first October 26
Median at 32°F
last March 31, first November 4
Median at 28°F
last March 20, 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 30Apr 22Apr 19Apr 16Apr 13Apr 10Apr 7Apr 3Mar 30
32°FApr 14Apr 9Apr 5Apr 3Mar 31Mar 29Mar 26Mar 22Mar 16
28°FApr 2Mar 31Mar 27Mar 24Mar 20Mar 17Mar 13Mar 8Mar 1
24°FMar 26Mar 21Mar 17Mar 13Mar 8Mar 3Feb 28Feb 22Feb 14
20°FMar 19Mar 11Mar 5Feb 28Feb 21Feb 14Feb 9Feb 2Jan 25
16°FMar 5Feb 24Feb 13Feb 6Feb 1Jan 30Jan 23Jan 17Jan 7

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 14Oct 19Oct 21Oct 24Oct 26Oct 29Nov 1Nov 3Nov 6
32°FOct 22Oct 27Oct 31Nov 1Nov 4Nov 6Nov 10Nov 13Nov 19
28°FNov 2Nov 6Nov 9Nov 12Nov 15Nov 18Nov 23Nov 28Dec 4
24°FNov 12Nov 17Nov 22Nov 26Nov 30Dec 3Dec 8Dec 16Dec 26
20°FNov 25Dec 1Dec 7Dec 12Dec 20Dec 25Jan 1Jan 6Jan 13
16°FDec 10Dec 18Dec 27Jan 1Jan 5Jan 11Jan 15Jan 20Feb 2

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°F215209203200195192187182176
32°F237231226222218215211205200
28°F264256250246241237232226218
24°F299288280272267261257251242
20°F333322313305299293286278268
16°F365354345337331325318307296

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
88% 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
3,699
Cooling degree days, base 65°F
1,514
Growing degree days, base 40°F
7,282
Growing degree days, base 45°F
5,803
Growing degree days, base 50°F
4,495
Growing degree days, base 55°F
3,347
Growing degree days, base 60°F
2,349

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January814020
February650022
March5027109
April22938286
May69126523
June7308751
July0433897
August1368832
September25196621
October20534308
November474396
December724030

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 7.3 km from Caswell 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 USC00319704 (Yanceyville 4 Se). Public domain.