Shell Point climate

Shell Point Frost Dates and Growing Season

NOAA 1991-2020 normals for Charleston Intl AP, 13.7 km from Shell Point, elevation 40 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Charleston Intl AP. 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 7 and the first fall freeze around November 27, a growing season of about 266 days.

Median at 36°F
last March 21, first November 13
Median at 32°F
last March 7, first November 27
Median at 28°F
last February 20, first December 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 6Mar 31Mar 29Mar 24Mar 21Mar 18Mar 14Mar 8Feb 28
32°FMar 27Mar 20Mar 15Mar 11Mar 7Mar 3Feb 27Feb 22Feb 12
28°FMar 14Mar 7Mar 1Feb 25Feb 20Feb 12Feb 5Jan 31Jan 21
24°FMar 3Feb 22Feb 12Feb 4Jan 31Jan 27Jan 19Jan 12Jan 2
20°FFeb 11Feb 1Jan 28Jan 23Jan 18Jan 12Jan 6Jan 1Dec 23
16°FJan 31Jan 27Jan 20Jan 17Jan 15Jan 11Jan 9Jan 4Jan 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°FNov 1Nov 4Nov 7Nov 10Nov 13Nov 16Nov 20Nov 26Dec 1
32°FNov 8Nov 13Nov 19Nov 23Nov 27Dec 1Dec 4Dec 11Dec 21
28°FNov 21Nov 29Dec 3Dec 8Dec 15Dec 22Dec 30Jan 4Jan 13
24°FDec 4Dec 14Dec 22Dec 28Jan 1Jan 6Jan 11Jan 18Jan 29
20°FDec 14Dec 25Dec 31Jan 4Jan 8Jan 13Jan 17Jan 23Jan 31
16°FDec 30Jan 3Jan 6Jan 10Jan 13Jan 16Jan 18Jan 23Jan 31

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°F266257249244239234230224217
32°F298287279272266261254246238
28°F334325316308301294287278267
24°F365355345337332326318307296
20°F365365365365364355345336328
16°F365365365365365365365365360

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
99% of years
24°F or colder
87% of years
20°F or colder
51% of years
16°F or colder
14% 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
1,844
Cooling degree days, base 65°F
2,435
Growing degree days, base 40°F
9,758
Growing degree days, base 45°F
8,020
Growing degree days, base 50°F
6,385
Growing degree days, base 55°F
4,901
Growing degree days, base 60°F
3,579

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4834112
February3527140
March22731293
April7599475
May9266722
June0434884
July05421,007
August0510975
September2357805
October56143553
November23432269
December4089151

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 13.7 km from Shell Point. 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 USW00013880 (Charleston Intl AP). Public domain.