South Carolina Annual Temperatures and Extremes

South Carolina's Temperature Records

Hottest temperature ever recorded: 111 F, Camden, north-central South Carolina, 6/18/1954 Coldest temperature ever recorded: -19 F, Caesars Head, northwestern South Carolina, 1/21/1985 Hottest location ranked by highest average annual temperature: Charleston, southeastern South Carolina, 66.5 F Coldest location ranked by lowest average annual temperature: Caesars Head, northwestern South Carolina, 54.4 F The summer of 2010 was Charleston's hottest summer on record. From June-August,  the average temperature was 83.1 degrees, beating the old record of 82.6 F set in 1998. Additional records set included the most consecutive days                            above 90 degrees with 74 days (old record was 70 in 1990) and the most nights with lows above 75 degrees with 53                               days (old record was 45 in 1998.)

Some factors affecting temperatures in South Carolina are elevation, latitude and distance inland from the coast. All three of these work together in South Carolina. Lower temperatures can be expected in the Upper Piedmont and Mountain Regions, where latitude, elevation and distance inland all have large values. Higher temperatures are found along the southern coast. Annual average temperatures are almost 10 degrees lower in the extreme Upper Piedmont than along the coast between Charleston and Savannah. Except for small-scale and local irregularities, there is a gradual decrease in annual average temperature northwestward from 67 at the coast to 58° F at the edge of the mountains. Within the Mountain Region, variations are great over short horizontal distances. Thus, variations in temperature are due almost entirely to elevation differences. Low temperatures are common in the Mountain Region or extreme Upper Piedmont during the winter. The lowest on record is -19° F at Caesars Head January 21, 1985. The air over the coastal water is cooler than the air over the land in summer and warmer than the air over land in winter and this has a modifying effect on the temperatures near the coast. Maximum summer temperatures of 111° F have been reached a few times at inland locations for the State record. Maximum temperatures in summer are reduced slightly in areas where afternoon cloudiness and rain are persistent. Such an area is found along the Outer Coastal Plain where sea breezes produce clouds and rain during the day, but dissipate at night. Another effect is the drainage of cold air, mostly October - April, into some of the river valleys causing low temperatures to be several degrees colder than they would be otherwise. One example of this takes place in a rather deep section of the Broad River valley from Lockhart to just north of Columbia.

The growing season for most crops is limited by the fall and spring freezes. The freeze-free period, the time elapsing between the last temperature of 32° F in the spring and the first in the fall, is quite important to agriculture. The average length of the freeze-free period varies from about 200 days in the coldest area to about 280 days along the south coast, but in the area where most of the major crops are grown it is from 210 to 235 days. The average date of the last freezing temperature in spring ranges from early March in the south to the first of April in the north. The fall dates range from late October in the north to late November in the south. Freezes have occurred as much as four weeks later than the average date in spring and three weeks earlier than the average date in the fall. The minimum temperature is 32° F or less on 50 to 70 days in the Upper Piedmont and 10 days near the coast. Counties in the Inner Coastal Plain and the Sand Hills area have maximum temperatures of 90° F or more on about 80 days. There are 30 such days along the coast and 10 to 30 in the mountains.

South Carolina precipitation averages and extremes, Top 10 climate extremes, precipitation data for all U.S. states
Data source: National Climatic Data Center