Climate of South Carolina

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South Carolina has a humid subtropical climate, with hot summers and mild winters. On average, between 40 inches (1,000 mm) and 80 inches (2,000 mm) of precipitation falls annually across the state. Tropical cyclones, and afternoon thunderstorms due to hot and humid conditions, contribute to precipitation during the summer and sometimes fall months, while extratropical cyclones contribute to precipitation during the fall, winter, and spring months. Tornadoes happen mostly in the spring with a secondary peak in November. Hail and damaging winds often occur in summertime thunderstorms. Tornadoes are very uncommon in the summer unless a tropical disturbance were to spawn one.

Temperatures[edit]

South Carolina has a humid subtropical climate (Köppen climate classification Cfa), although high elevation areas in the "Upstate" area have less subtropical characteristics than areas on the Atlantic coastline. In the summer, South Carolina is hot and humid with temperatures during the day averaging near 90 °F (32 °C) across most of the state with overnight lows near 70 °F (21 °C). Winter temperatures are much less uniform. Coastal areas of the state have very mild winters with high temperatures averaging about 60 °F (16 °C) and overnight lows close to 38 °F (3 °C). Further inland in the Piedmont, temperatures average between 50 °F (10 °C) during the day and 32 °F (0 °C) at night.

Event Measurement Date Location County
Highest temperature[1][2] 113 °F (45.0 °C) Jun. 29, 2012 USC Columbia Richland, South Carolina
Lowest temperature[3][4] −19 °F (−28.3 °C) January 21, 1985 Caesars Head Greenville

Precipitation[edit]

Annual average precipitation in South Carolina

While precipitation is abundant the entire year in almost the entire state, the coastline tends to have a slightly wetter summer, while inland March tends to be the wettest month. During the cold season, extratropical cyclones is the main cause of precipitation, while during the summer, tropical cyclones and thunderstorms forming due to afternoon heating are the main causes of precipitation. A lee side rain shadow from the Appalachian Mountains lowers annual precipitation across central portions of the state.[5] Inland sections average 40 inches (1,000 mm) to 50 inches (1,300 mm) of rainfall, while near the coast 50 inches (1,300 mm) to 60 inches (1,500 mm), and the Piedmont receives 70 inches (1,800 mm) to 80 inches (2,000 mm) of precipitation.[6] Winter precipitation is determined in large by the El Niño-Southern Oscillation. During El Niño events, the jet stream is further south and east across the U.S., thus leading to cooler and wetter winters in South Carolina, while La Niña keeps the jet stream further north and west causing warmer and drier winters.

Event Measurement Date Location County
Most precipitation in a year for a single area 120.21 inches (3,053 mm) ? Hogback Mountain Greenville
Least precipitation in a year for a single area 22.69 inches (58 cm) ?
Event Measurement Date Location County
Greatest 24-hour rainfall[7][8][9] 17.00 inches (432 mm) August 27, 1995 Antreville Abbeville

Snowfall and ice[edit]

Annual snowfall across inland South Carolina is very small, and in coastal areas several years might pass without any measurable snowfall. The snowiest location in the state averages 12 inches (30 cm) of snow a year in the Blue Ridge Mountains of the state. Freezing rain is more common than snow and even rain across much of the state in the winter months. Along the coast snowfall is very rare, with only a few snow events on record. Charleston averages less than 1 inch annually, and often 5 to 10 years might pass without any snowfall.

Event Measurement Date Location County
Greatest 24-hour snowfall[10] 24 inches (61 cm) February 10–11, 1973 Rimini Clarendon
Most snowfall from one storm [11] 28.9 inches (73 cm) February 15–17, 1969 Caesars Head Greenville

Tropical cyclones[edit]

Hurricane Hugo (1989)

The state is prone to tropical cyclones. This is an annual concern during hurricane season, which is from June through November. The peak time of vulnerability for the southeast Atlantic coast is from early August to early October when tropical cyclone frequency is highest.[12] Major hurricanes can impact the Palmetto state, though there are no category 5 impacts on record.[13] Two of the stronger hurricanes to strike South Carolina in recent times are Hurricane Hazel (1954) and Hurricane Hugo (1989), which were of category 4 strength. For weaker systems, rainfall and spin-up tornadoes in the outer bands are the main impacts to the state. The wettest known tropical cyclone to impact South Carolina was a tropical depression named Jerry in 1995 which stalled nearby and had previously been a tropical storm across Florida.[14]

Event Measurement Date Location County
Wettest tropical cyclone[9] 17.00 inches (432 mm) Tropical Storm Jerry
(1995)
Antreville Abbeville

Thunderstorms and tornadoes[edit]

South Carolina averages around 64 days of thunderstorm activity per year. Most thunderstorms occur during the summer. South Carolina is vulnerable to tornadoes. Some notable tornadoes have struck South Carolina and the state averages around 14 tornadoes annually.[15] There have been no F-5 tornadoes on record but over a dozen F-4 tornadoes have occurred in many counties in South Carolina.

Monthly normals and extremes for select cities[edit]

Climate data for Greenville, South Carolina (Greenville–Spartanburg Int'l), 1981–2010 normals,[a] extremes 1884–present[b]
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °F (°C) 82
(28)
81
(27)
91
(33)
94
(34)
100
(38)
105
(41)
107
(42)
105
(41)
101
(38)
97
(36)
86
(30)
79
(26)
107
(42)
Mean maximum °F (°C) 69.4
(20.8)
72.5
(22.5)
80.8
(27.1)
86.0
(30)
90.2
(32.3)
95.1
(35.1)
97.3
(36.3)
95.9
(35.5)
91.1
(32.8)
84.4
(29.1)
77.1
(25.1)
69.5
(20.8)
98.6
(37)
Average high °F (°C) 52.4
(11.3)
56.6
(13.7)
64.5
(18.1)
72.8
(22.7)
80.2
(26.8)
87.5
(30.8)
90.3
(32.4)
88.6
(31.4)
82.2
(27.9)
72.8
(22.7)
63.5
(17.5)
54.1
(12.3)
72.1
(22.3)
Average low °F (°C) 32.0
(0)
34.9
(1.6)
41.2
(5.1)
48.3
(9.1)
57.2
(14)
65.8
(18.8)
69.4
(20.8)
68.7
(20.4)
61.8
(16.6)
50.4
(10.2)
41.3
(5.2)
34.0
(1.1)
50.4
(10.2)
Mean minimum °F (°C) 14.6
(−9.7)
19.0
(−7.2)
24.2
(−4.3)
32.6
(0.3)
42.7
(5.9)
55.0
(12.8)
61.7
(16.5)
60.7
(15.9)
47.9
(8.8)
34.1
(1.2)
26.0
(−3.3)
18.1
(−7.7)
11.8
(−11.2)
Record low °F (°C) −6
(−21)
−5
(−21)
11
(−12)
22
(−6)
27
(−3)
40
(4)
53
(12)
50
(10)
32
(0)
25
(−4)
11
(−12)
3
(−16)
−6
(−21)
Average precipitation inches (mm) 3.82
(97)
3.97
(100.8)
4.52
(114.8)
3.36
(85.3)
3.76
(95.5)
3.80
(96.5)
4.80
(121.9)
4.48
(113.8)
3.43
(87.1)
3.44
(87.4)
3.70
(94)
4.11
(104.4)
47.19
(1,198.6)
Average snowfall inches (cm) 2.3
(5.8)
1.0
(2.5)
0.9
(2.3)
trace 0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0.1
(0.3)
0.4
(1)
4.7
(11.9)
Average precipitation days (≥ 0.01 in) 10.2 9.2 9.6 9.0 9.7 10.4 11.7 10.4 8.1 7.2 8.9 9.8 114.2
Average snowy days (≥ 0.1 in) 1.2 0.7 0.3 0.1 0 0 0 0 0 0 0.1 0.4 2.8
Average relative humidity (%) 65.8 62.6 62.1 60.7 68.5 70.5 74.0 75.6 75.8 70.9 68.2 67.7 68.5
Mean monthly sunshine hours 176.6 182.7 236.2 264.7 269.2 270.8 267.8 253.9 229.2 235.2 184.3 169.4 2,740
Percent possible sunshine 56 60 64 68 62 62 61 61 62 67 59 55 62
Source: NOAA (relative humidity 1962–1990, sun 1961–1990)[16][17][18]
Climate data for Columbia, South Carolina (Columbia Airport), 1981–2010 normals,[c] extremes 1887–present[d]
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °F (°C) 84
(29)
84
(29)
93
(34)
96
(36)
101
(38)
109
(43)
107
(42)
107
(42)
106
(41)
101
(38)
90
(32)
83
(28)
109
(43)
Mean maximum °F (°C) 73.7
(23.2)
77.6
(25.3)
83.9
(28.8)
89.3
(31.8)
94.0
(34.4)
98.5
(36.9)
100.2
(37.9)
98.9
(37.2)
94.5
(34.7)
88.2
(31.2)
80.9
(27.2)
75.3
(24.1)
101.6
(38.7)
Average high °F (°C) 56.0
(13.3)
60.3
(15.7)
68.2
(20.1)
76.3
(24.6)
83.8
(28.8)
90.0
(32.2)
92.7
(33.7)
90.7
(32.6)
85.2
(29.6)
76.1
(24.5)
67.3
(19.6)
58.2
(14.6)
75.4
(24.1)
Average low °F (°C) 33.7
(0.9)
36.8
(2.7)
43.0
(6.1)
50.4
(10.2)
59.5
(15.3)
68.2
(20.1)
71.6
(22)
71.0
(21.7)
64.2
(17.9)
52.1
(11.2)
42.3
(5.7)
35.3
(1.8)
52.3
(11.3)
Mean minimum °F (°C) 16.4
(−8.7)
20.6
(−6.3)
25.5
(−3.6)
33.2
(0.7)
44.1
(6.7)
56.6
(13.7)
63.5
(17.5)
62.0
(16.7)
49.0
(9.4)
34.4
(1.3)
26.2
(−3.2)
19.1
(−7.2)
14.7
(−9.6)
Record low °F (°C) −1
(−18)
−2
(−19)
4
(−16)
26
(−3)
34
(1)
44
(7)
54
(12)
53
(12)
40
(4)
23
(−5)
12
(−11)
4
(−16)
−2
(−19)
Average precipitation inches (mm) 3.58
(90.9)
3.61
(91.7)
3.73
(94.7)
2.62
(66.5)
2.97
(75.4)
4.69
(119.1)
5.46
(138.7)
5.26
(133.6)
3.54
(89.9)
3.17
(80.5)
2.74
(69.6)
3.22
(81.8)
44.59
(1,132.6)
Average snowfall inches (cm) 0.8
(2)
0.5
(1.3)
0.1
(0.3)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0.1
(0.3)
1.5
(3.8)
Average precipitation days (≥ 0.01 in) 9.9 9.1 8.6 8.0 7.7 10.5 11.8 10.5 7.3 7.0 7.3 9.0 106.7
Average snowy days (≥ 0.1 in) 0.5 0.3 0.1 0 0 0 0 0 0 0 0 0.1 1.0
Average relative humidity (%) 69.2 65.8 64.6 62.1 68.2 70.8 73.4 76.5 75.9 73.0 71.6 70.7 70.2
Mean monthly sunshine hours 172.7 180.7 237.3 269.6 292.9 280.0 286.0 263.3 239.8 235.0 193.8 175.0 2,826.1
Percent possible sunshine 55 59 64 69 68 65 65 63 64 67 62 57 64
Source: NOAA (relative humidity and sun 1961−1990)[19][20][21]
Climate data for Charleston Int'l, South Carolina (1981–2010 normals,[22] extremes 1938–present)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °F (°C) 83
(28)
87
(31)
90
(32)
95
(35)
99
(37)
103
(39)
104
(40)
105
(41)
99
(37)
94
(34)
88
(31)
83
(28)
105
(41)
Mean maximum °F (°C) 75.3
(24.1)
78.1
(25.6)
83.5
(28.6)
88.5
(31.4)
92.7
(33.7)
96.8
(36)
98.0
(36.7)
96.5
(35.8)
92.6
(33.7)
87.1
(30.6)
81.9
(27.7)
76.8
(24.9)
99.2
(37.3)
Average high °F (°C) 59.0
(15)
62.8
(17.1)
69.6
(20.9)
76.4
(24.7)
83.2
(28.4)
88.4
(31.3)
91.1
(32.8)
89.5
(31.9)
84.8
(29.3)
77.1
(25.1)
69.8
(21)
61.6
(16.4)
76.1
(24.5)
Average low °F (°C) 37.5
(3.1)
40.6
(4.8)
46.7
(8.2)
53.3
(11.8)
61.8
(16.6)
69.6
(20.9)
73.0
(22.8)
72.3
(22.4)
67.2
(19.6)
56.8
(13.8)
47.5
(8.6)
40.1
(4.5)
55.5
(13.1)
Mean minimum °F (°C) 21.4
(−5.9)
25.5
(−3.6)
30.4
(−0.9)
38.6
(3.7)
49.5
(9.7)
61.1
(16.2)
67.5
(19.7)
66.0
(18.9)
55.6
(13.1)
41.0
(5)
32.6
(0.3)
24.0
(−4.4)
18.8
(−7.3)
Record low °F (°C) 6
(−14)
12
(−11)
15
(−9)
29
(−2)
36
(2)
50
(10)
58
(14)
56
(13)
42
(6)
27
(−3)
15
(−9)
8
(−13)
6
(−14)
Average precipitation inches (mm) 3.71
(94.2)
2.96
(75.2)
3.71
(94.2)
2.91
(73.9)
3.02
(76.7)
5.65
(143.5)
6.53
(165.9)
7.15
(181.6)
6.10
(154.9)
3.75
(95.3)
2.43
(61.7)
3.11
(79)
51.03
(1,296.2)
Average snowfall inches (cm) trace 0.2
(0.5)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0.3
(0.8)
0.5
(1.3)
Average precipitation days (≥ 0.01 in) 9.6 8.6 7.9 7.7 7.8 11.9 13.0 13.2 10.0 7.3 7.0 8.7 112.7
Average snowy days (≥ 0.1 in) 0.1 0.2 0 0 0 0 0 0 0 0 0 0.2 0.5
Average relative humidity (%) 69.8 67.4 68.1 67.5 72.5 75.1 76.6 78.9 78.2 74.1 72.7 71.6 72.7
Mean monthly sunshine hours 179.3 186.7 243.9 275.1 294.8 279.5 287.8 256.7 219.7 224.5 189.5 171.3 2,808.8
Percent possible sunshine 56 61 66 71 69 65 66 62 59 64 60 55 63
Source: NOAA (relative humidity and sun 1961–1990)[23][24][25]
Climate data for Charleston, South Carolina (Downtown), 1981–2010 normals,[22] extremes 1893–present
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °F (°C) 82
(28)
83
(28)
94
(34)
94
(34)
99
(37)
104
(40)
103
(39)
103
(39)
100
(38)
95
(35)
87
(31)
81
(27)
104
(40)
Mean maximum °F (°C) 71.3
(21.8)
74.6
(23.7)
79.7
(26.5)
84.6
(29.2)
90.0
(32.2)
94.0
(34.4)
96.2
(35.7)
94.2
(34.6)
91.2
(32.9)
85.2
(29.6)
79.0
(26.1)
73.9
(23.3)
97.4
(36.3)
Average high °F (°C) 56.7
(13.7)
59.6
(15.3)
65.0
(18.3)
72.0
(22.2)
78.7
(25.9)
84.5
(29.2)
87.6
(30.9)
86.4
(30.2)
82.0
(27.8)
74.6
(23.7)
67.3
(19.6)
59.5
(15.3)
72.8
(22.7)
Average low °F (°C) 42.8
(6)
45.5
(7.5)
51.6
(10.9)
58.8
(14.9)
67.1
(19.5)
74.0
(23.3)
76.9
(24.9)
76.1
(24.5)
71.8
(22.1)
62.5
(16.9)
53.6
(12)
45.6
(7.6)
60.5
(15.8)
Mean minimum °F (°C) 27.5
(−2.5)
31.6
(−0.2)
36.4
(2.4)
44.8
(7.1)
55.6
(13.1)
66.5
(19.2)
71.0
(21.7)
69.8
(21)
61.6
(16.4)
48.1
(8.9)
39.1
(3.9)
30.2
(−1)
24.8
(−4)
Record low °F (°C) 10
(−12)
7
(−14)
22
(−6)
36
(2)
45
(7)
52
(11)
61
(16)
59
(15)
50
(10)
37
(3)
17
(−8)
12
(−11)
7
(−14)
Average precipitation inches (mm) 2.94
(74.7)
2.51
(63.8)
3.30
(83.8)
2.53
(64.3)
2.16
(54.9)
4.65
(118.1)
5.40
(137.2)
6.71
(170.4)
5.76
(146.3)
3.67
(93.2)
2.19
(55.6)
2.60
(66)
44.42
(1,128.3)
Average precipitation days (≥ 0.01 in) 9.0 8.0 7.8 6.9 6.6 10.0 11.3 11.3 8.9 6.6 6.3 8.6 101.3
Source: NOAA[23][26]

See also[edit]

Notes[edit]

  1. ^ Mean monthly maxima and minima (i.e. the expected highest and lowest temperature readings at any point during the year or given month) calculated based on data at said location from 1981 to 2010.
  2. ^ Official records for Greenville kept April 1884 to 10 December 1941 at downtown, 11 December 1941 to 14 October 1962 at Greenville Downtown Airport, and at Greenville–Spartanburg Int'l near Greer since 15 October 1962. For more information, see Threadex
  3. ^ Mean monthly maxima and minima (i.e. the expected highest and lowest temperature readings at any point during the year or given month) calculated based on data at said location from 1981 to 2010.
  4. ^ Official records for Columbia were kept at downtown from June 1887 to December 1947, and at Columbia Airport since January 1948. For more information, see Threadex

References[edit]

  1. ^ "South Carolina Record Maximum Temperatures and Date". South Carolina State Climatology Office. South Carolina Department of Natural Resources. Retrieved 4 February 2010. 
  2. ^ "Map of South Carolina Record Maximum Temperatures and Year". South Carolina State Climatology Office. South Carolina Department of Natural Resources. Retrieved 4 February 2010. 
  3. ^ "South Carolina Record Minimum Temperatures and Date". South Carolina State Climatology Office. South Carolina Department of Natural Resources. Retrieved 4 February 2010. 
  4. ^ "Map of South Carolina Record Minimum Temperatures and Year". South Carolina State Climatology Office. South Carolina Department of Natural Resources. Retrieved 4 February 2010. 
  5. ^ South Carolina State Climatology Office. South Carolina Climate. Retrieved on 2008-03-18.
  6. ^ National Atlas.gov. Average annual precipitation for South Carolina. Archived 2008-08-16 at the Wayback Machine. Retrieved on 2008-03-08.
  7. ^ "South Carolina Maximum 24-Hour Precipitation". South Carolina State Climatology Office. South Carolina Department of Natural Resources. Retrieved 5 February 2010. 
  8. ^ "Map of South Carolina Record 24 Hour Precipitation and Date". South Carolina State Climatology Office. South Carolina Department of Natural Resources. Retrieved 5 February 2010. 
  9. ^ a b "August 27, 1995". South Carolina State Climatology Office. South Carolina Department of Natural Resources. Retrieved 5 February 2010. 
  10. ^ "South Carolina Maximum 24-Hour Snow". South Carolina State Climatology Office. South Carolina Department of Natural Resources. Retrieved 4 February 2010. 
  11. ^ "South Carolina Historical Maximum Snowfall events". South Carolina State Climatology Office. South Carolina Department of Natural Resources. Retrieved 7 November 2011. 
  12. ^ National Hurricane Center. Graphic showing seasonal activity by date. Retrieved on 2008-03-18.
  13. ^ Eric S. Blake, Edward N. Rappaport, and Chris Landsea. The Deadliest, Costliest, and Most Intense United States Tropical Cyclones From 1851 to 2006 (and other frequently requested hurricane facts).
  14. ^ [[National Hurricane Center] ainblk.gif Tropical Storm Jerry Color-Filled Rainfall Graphic.] Retrieved on 2008-03-18.
  15. ^ National Climatic Data Center. Annual average number of tornadoes. Retrieved on 2006-10-24.
  16. ^ "NowData - NOAA Online Weather Data". National Oceanic and Atmospheric Administration. Retrieved 2016-09-04. 
  17. ^ "Station Name: SC GREER". National Oceanic and Atmospheric Administration. Retrieved 2016-09-04. 
  18. ^ "WMO Climate Normals for GREENVILLE/G-SPARTANBURG, SC 1961–1990". National Oceanic and Atmospheric Administration. Retrieved 2016-09-04. 
  19. ^ "NowData – NOAA Online Weather Data". National Oceanic and Atmospheric Administration. Retrieved 2016-09-04. 
  20. ^ "Station Name: SC COLUMBIA". National Oceanic and Atmospheric Administration. Retrieved 2016-09-04. 
  21. ^ "WMO Climate Normals for COLUMBIA/METRO ARPT SC 1961–1990". National Oceanic and Atmospheric Administration. Retrieved 2016-09-04. 
  22. ^ a b Mean monthly maxima and minima (i.e. the expected highest and lowest temperature readings at any point during the year or given month) calculated based on data at said location from 1981 to 2010.
  23. ^ a b "NowData - NOAA Online Weather Data". National Oceanic and Atmospheric Administration. Retrieved 2016-09-04. 
  24. ^ "Station Name: SC CHARLESTON INTL AP". National Oceanic and Atmospheric Administration. Retrieved 2014-05-09. 
  25. ^ "WMO Climate Normals for CHARLESTON/MUNICIPAL, SC 1961–1990". National Oceanic and Atmospheric Administration. Retrieved 2016-09-04. 
  26. ^ "Station Name: SC CHARLESTON CITY". National Oceanic and Atmospheric Administration. Retrieved 2014-05-09.