Constantia climate

Constantia Frost Dates and Growing Season

NOAA 1991-2020 normals for Camden, 15.8 km from Constantia, elevation 580 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Camden. 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 12 and the first fall freeze around October 5, a growing season of about 144 days.

Median at 36°F
last May 26, first September 24
Median at 32°F
last May 12, first October 5
Median at 28°F
last April 30, first October 19

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°FJun 9Jun 4Jun 1May 30May 26May 23May 20May 16May 10
32°FMay 29May 23May 18May 15May 12May 8May 5May 1Apr 27
28°FMay 17May 11May 6May 2Apr 30Apr 27Apr 24Apr 21Apr 16
24°FMay 2Apr 26Apr 22Apr 20Apr 17Apr 14Apr 10Apr 7Apr 3
20°FApr 18Apr 14Apr 10Apr 7Apr 5Apr 3Apr 1Mar 31Mar 26
16°FApr 8Apr 5Apr 2Apr 1Mar 31Mar 28Mar 24Mar 21Mar 17

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 11Sep 15Sep 19Sep 22Sep 24Sep 27Sep 30Oct 2Oct 7
32°FSep 22Sep 27Sep 30Oct 2Oct 5Oct 7Oct 11Oct 16Oct 21
28°FOct 1Oct 6Oct 10Oct 15Oct 19Oct 23Oct 27Nov 1Nov 4
24°FOct 15Oct 22Oct 28Oct 31Nov 2Nov 5Nov 8Nov 12Nov 16
20°FNov 1Nov 3Nov 7Nov 10Nov 13Nov 16Nov 19Nov 23Nov 29
16°FNov 11Nov 15Nov 18Nov 21Nov 25Nov 28Dec 1Dec 4Dec 10

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°F142135130126121117113108102
32°F166159154149144140135130123
28°F194187180176171166161154147
24°F219211206202198193188182173
20°F240234229225221217213209203
16°F261252247243240236232227221

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
7,590
Cooling degree days, base 65°F
367
Growing degree days, base 40°F
4,083
Growing degree days, base 45°F
3,065
Growing degree days, base 50°F
2,184
Growing degree days, base 55°F
1,428
Growing degree days, base 60°F
812

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,40101
February1,23600
March1,09706
April665245
May32619207
June10466414
July27132570
August41107532
September18439313
October506285
November825012
December1,17801

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 15.8 km from Constantia. 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 USC00301110 (Camden). Public domain.