South Carolina 2018 Weather in Review

South Carolina State Climatology Office
South Carolina Department Natural Resources
P.O. Box 167
Columbia, SC 29202

JANUARY

Two thousand eighteen began with the coldest first week of January in 130 years of record keeping for the state. New Year's Day was clear, cold and dry with a low temperature of 5.4 degrees F reported at the station atop Sassafras Mountain. Other stations across the state, including Columbia, Orangeburg and Charleston, only reached an afternoon high temperature of 34 degrees F and the following day, Jocassee reported a morning low temperature of 3 degrees F that "warmed" to 26 degrees F that afternoon. The Arctic invasion of cold air continued and on Wednesday, January 3, a rapidly deepening offshore low-pressure system provided moisture aloft for a major snow event for the state. Freezing rain began early over Beaufort County before transitioning to snow before noon. Snowfall was heaviest at the coast, and as the offshore low deepened, convective banding developed that brought 3-6 inches of snow north into Marlboro, Dillon and Marion counties. The runways at the Charleston Air Force Base that received 5.3 inches of snow on the 3rd were closed until Sunday, January 7. Temperatures through mid-January swung back and forth between bitter cold and record warmth. On Thursday, January 11, afternoon temperatures reached 77 degrees in Florence and Charleston after Dillon and Darlington reported a morning low of 37 degrees F. Rock Hill set a date record high temperature of 74 degrees F, surpassing the previous date record of 69 degrees F set in 2000. One week later, clear skies and cold air returned, and Chesnee reported a morning low temperature of 5 degrees F. The Charleston Air Force Base reached a high temperature of 47 degrees F. On Friday, January 19, Chesnee reported another low morning temperature of 6 degrees F and 2.0 inches of snow still on the ground. Orangeburg warmed to 64 degrees F under clear skies and southwest winds. The Lancaster COOP station reported a Saturday morning temperature of 8 degrees F. On Sunday, January 20, Columbia Metro posted a 73-degree afternoon high temperature after a 31-degree morning start. Despite the snow and some rainfall during the month, the dry conditions exacerbated the state's drought conditions and low stream flow levels.

FEBRUARY

The month of February may have started cold, but soon spring and summerlike temperatures took hold across the state. On Thursday, February 1, Ninety-Nine Islands reported a 15-degree low temperature. As the high pressure slid eastward Thursday afternoon, a southwesterly flow and clear skies helped Barnwell warm to 71 degrees. After a 33-degree low temperature the following morning, both North Myrtle Beach and Columbia reached an afternoon high temperature of 61 degrees. A vigorous squall line passed over the state on Wednesday, February 7. Winds gusted to 45 mph at Florence and the Greer National Weather Service Office reported 1.65 inches of rainfall. Diurnal heating and a persistent southerly flow warmed Walterboro, Jamestown and Holly Hill to 76 degrees ahead of the squall line. A cold frontal passage on Wednesday evening ushered in cool, dry, Canadian high pressure for the start of February 8. Union had a morning low temperature of 27 degrees and the Charleston Air Force Base only warmed to 65 degrees. Maximum temperature records were broken by more than 10 degrees at multiple locations across the state on February 16; including an observed high temperature at Myrtle Beach Grand Strand Airport of 81 degrees, which broke the previous record of 69 in 2001. Anomalously warm temperatures tied and a total of 222 new date record high temperatures across the state every day during February 19-25. Of those records, 139 new date record high temperatures were set by two or more degrees. On February 21, Little Mountain reported a date record high temperature of 82 degrees, surpassing the previous record of 77 degrees set back in 1897.

MARCH

The first day of March, Columbia Metro Airport and Orangeburg reported reaching an afternoon high temperature of 82 degrees. A sharp squall line swept over the state during the afternoon downing numerous trees across the Midlands and Pee Dee. Shaw Air Force Base in Sumter recorded 41-mph sustained winds gusting to 55 mph at 4:17 PM, and a 16-degree temperature drop in one hour after the squall line's passage. Santuck reported 1.45 inches of rainfall from the passing squall. High pressure migrated southeast of the state by midday Saturday, March 10. With a more southerly surface flow in place, Columbia and Charleston reached 71 degrees that afternoon. A trough developed over the SC-NC border late in the day triggering scattered, light rain showers over the Upstate. Clear and dry conditions continued on Thursday, March 15. Cedar Creek had a morning low temperature of 21 degrees. Greenville and Columbia reached an afternoon high of 70 degrees. Barnwell, Charleston and Florence reported afternoon high temperatures of 79 degrees. A weak frontal boundary hovered over the state during the weekend. The boundary produced a band of light rain that tracked across the state on March 17 before dissipating on the coast late in the day. A strong cold front on March 20 produced a pre-dawn tornado in Allendale County. The EF0 rated tornado touched down at 3:43 AM into the tops of trees between SC Highway 3 and Alleluia Road. The 75-yard wide tornado traveled for 0.37 miles. The NWS damage survey estimated the maximum wind speed to be 75 mph and noted damage confined to just isolated snapped and small downed trees. By the end of the month, many stations were already reporting rainfall deficits, including nearly seven inches at Orangeburg and Savannah, to just under an inch in the Upstate.

APRIL

April 2018 started clear and cool, with many stations reporting record low temperatures during the first part of the month. Rainfall during the first part of the month was associated with weak frontal boundaries that passed through the state. On April 15, a sprawling, deepening low-pressure system threatened the state with a strong cold front and a squally, pre-frontal trough. Before the frontal passage, Clemson and Greenwood reported a morning low temperature of 47 degrees. The Charleston Airport reached 82 degrees. The pre-frontal trough produced numerous strong thunderstorms, periods of blinding torrential rain and strong wind gusts as it thundered across the state. Columbia Metro Airport observed a 74-mph wind gust at 2:24 PM. Sustained winds reached 33 mph. The Charleston Airport reported 36-mph winds gusting to 50 mph later that afternoon during a strong thunderstorm. Strong thunderstorm cells in the trough produced five tornadoes. The five tornadoes and straight-line wind gusts uprooted numerous trees, damaged structures and vehicles, and knocked out power to 50,000 SCE&G customers. Florence reported a rainfall total of 2.48 inches. The National Weather Service in Greer reported a rainfall total of 2.31 inches. Another round of unseasonably cold weather was observed across the Palmetto State at the end of April, with average temperatures close to 10 degrees below normal. Despite the rainfall throughout the month, the drought conditions continued to plague portions of the state, especially around the Midlands and the counties that bordered the Savannah River.

MAY

From colder than normal temperatures to maximum temperatures close to 90 degrees, the first week of May started with a quick flip to summer-like weather across the state. Even with scattered rain showers, high pressure dominated the weather pattern, and on Friday, May 10, high-temperature records for the date were either tied or broken at multiple locations as the temperatures soared into the mid-90’s, including a 98-degree value reported in Orangeburg. The extremely warm, above-normal temperatures continued through the middle of the month, with some stations reporting five or more days with maximum temperatures above 90 degrees. Above-average rainfall during May, especially during the latter half of the month from Subtropical Storm Alberto, helped ease persistent drought conditions across the state. According to State Climatologist Hope Mizzell, “The last time the entire state was drought-free was July 8, 2016.” The major reservoirs were near their target levels, and streams, rivers and ground-water levels were up due to the recent rains, ranging from five to nearly 20 inches in different portions of South Carolina. Most of the CoCoRaHS stations in Oconee County reported more than nine inches of rain during May. Stations in Beaufort reported less than two inches during the month. The statewide precipitation total for May was 6.19 inches, making it the sixth wettest May on record.

JUNE

Hot and humid conditions were reported on the first day of June at the USC and the Witherbee RAWS stations, which recorded high temperatures of 94 degrees. The heat and humidity dominated the weather through mid-month, and the COOP observer at USC in Columbia reported an afternoon high temperature of 100 degrees. The NWS station at the Columbia Metro reached 98 degrees after a morning low temperature of 74 degrees on June 15. The same day scattered, strong storms triggered by a weak frontal boundary produced one-inch hail near Socastee and Garden City in Horry County, and a wind gusts of 60 mph were recorded at Shaw Air Force Base. At the end of the month, the combination of an upper-level disturbance and weak cold front produced a warm and humid environment for the state during the beginning of the week. The result was strong to severe thunderstorms on June 25 through June 27. On Monday, June 25, quarter- to golf ball-sized hail was reported in Spartanburg, and a wind gust of 57 mph was reported from the Florence Regional Airport that evening. Multiple locations in the Upstate and Midlands reported storm damage (downed trees and power outages) due to the strong winds associated with the thunderstorms. On the same day, hail (dime- to penny-sized) was observed in Beaufort County, and, earlier that afternoon, Beaufort Marine Corps Air Station also reported heat indices values of 115 degrees.

JULY

The hot and humid temperatures from the end of June carried over into the beginning of July, and the NWS station at Caesars Head State Park (elev. 3200') reported a mild 74 degrees for a high temperature on the first day of the month. Southerly flow led to increased moisture, which combined with the above normal temperatures to cause heat indices up to 105 degrees for multiple days in the Midlands. Tropical Storm Chris remained well offshore, posing no direct threat to the South Carolina coast. Multiple NWS stations reported maximum temperatures at or above 100 degrees during the middle of the month, including 103 degrees reported at the Columbia Metro Airport on July 11, which broke the previous record of 102 back in 1993. Training thunderstorms during the morning hours on Friday, July 20, produced heavy rains throughout a few hours along the southeastern coast. The freshwater flooding in downtown Charleston closed many residential streets, including major roads such as Highway 17. Multiple reports of stranded motorists and water waist high in some locations of Charleston prompted law enforcement officials to encourage people to stay away from downtown. The heaviest rains were confined closer to the coast. Two downtown CoCoRaHS stations reported over eight inches (8.76 inches at 2 S North Charleston and 8.37 inches at 2 SW Daniel Island), with many more over six inches. Further inland, the Charleston International Airport measured 1.25 inches, and the National Weather Service Office in Charleston received 2.45 inches at their location. Additional heavy rains fell over portions of Horry and Georgetown counties with rainfall totals up to six inches in some locations.

AUGUST

August started with an unsettled weather pattern, with multiple rounds of rain and thunderstorms rolling through the Palmetto State. Thunderstorms that produced the strong winds were accompanied by heavy rains, which closed multiple roads in the towns of Knightsville and Summerville in Dorchester County. The South Carolina Highway Patrol reported a tree down on Interstate 26 near Little Mountain in Newberry County. The typical late-summer hot and humid weather conditions continued through the first half of the month. Dewpoints remained in the upper 70's in the Midlands and Upstate through the afternoon hours, pushing the heat indices values to around 105 degrees. The low morning temperature highs were in the 70's to near 80 degrees along the coast, with the station at Myrtle Beach reporting a minimum temperature of 78 degrees on August 11. During the week of August 20-26, the only areas to receive measurable rainfall were in Beaufort and Jasper counties in the Lowcountry and portions of the Piedmont and Upstate. Most of the rainfall that fell across the state that week was less than one inch, with higher amounts in localized areas. Another week with a lack of rainfall elsewhere across the state led to a continued drop off in streamflow values in some of the area creeks and rivers, especially in the upper Pee Dee region. The Lynches River near Bishopville reported streamflows of 95.8 cubic feet per second (CFS), below the minimum flow of 109 CFS set in 2002.

SEPTEMBER

The continued period of below-normal rainfall through the first part of September led members of the U.S. Drought Monitor to hold the dry (D0) and moderate drought conditions (D1) to include much of the Pee Dee region, including Lancaster County and parts of Chester, Chesterfield, Fairfield and Kershaw counties. Multiple record high minimum temperatures were tied or broken on Thursday, September 13 including the observed low of 74 degrees at the Greenville-Spartanburg Airport, which broke the old record of 71 degrees in 2007. Hurricane Florence made landfall at 7:15 a.m. on Friday, September 14, near Wilmington as a Category 1 hurricane with winds of about 90 miles an hour. The NWS station in Myrtle Beach reported a peak wind gust of 61 mph and other observing stations recorded gusts up to 50 mph throughout the Pee Dee Region. After making landfall, the storm slowed down, moving at two mph, exacerbating the impacts from the torrential rainfall and flooding across the Carolinas. Rainfall totals across the Pee Dee region the morning of Saturday, September 15, ranged from three to eight inches and the maximum 24-hour rainfall totals of 10.82 inches in Chesterfield and 10.75 inches in Cheraw were reported Sunday morning. The amount at Cheraw surpassed the previous daily rainfall record by 7.88 inches, set back in 1999 by Hurricane Floyd. Two CoCoRaHS observers in the Loris area measured rainfall totals from Hurricane Florence of over 23 inches, while the storm total from the NWS station in Cheraw was 22.79 inches. Extensive flooding continued long after Florence moved through the area, with record crests set along numerous rivers.

OCTOBER

Tranquil weather and above-normal temperatures started the month of October before Hurricane Michael’s landfall along the Florida Panhandle made it the third most intense Atlantic hurricane on record to make landfall in the United States. The hurricane continued to track northeastward across Georgia during the evening hours of October 10 and weakened to a tropical storm just before midnight. The storm produced four tornadoes that touched down in Orangeburg and Richland counties; the strongest was an EF1 near Eastover. Rains from Michael ranged across the state between two to three inches, with three to five inches in the Midlands and Upstate with locally heavier amounts. Unlike Hurricane Florence, Hurricane Michael was a fast-moving storm system that raced across the state at nearly 20 mph. The speed at which Hurricane Michael moved created the scenario for more impacts from the wind than there had been with Hurricane Florence. Some of the peak wind gusts associated with Michael in the Midlands were a 53-mph wind gust at the Orangeburg Municipal Airport and a 43-mph wind gust at the Rock Hill Airport. Along the coast, the National Data Buoy Center's instruments on the Capers Nearshore Buoy reported a 60-mph gust, while a station on Daufuskie Island reported a peak gust of 59 mph, and the Grand Strand Airport reported a gust of 53 mph. The strong winds and rainfall from Michael, along with the still saturated soils from Florence, combined to bring down trees and cause widespread power outages across the state. By the evening hours on Thursday, October 11, Michael had moved into North Carolina and Virginia. A vigorous cold front pushed through the state near the end of the month, bringing cooler and dry air into the state, bringing a break from above normal temperatures.

NOVEMBER

The month’s first week started with warm temperatures, with stations in the Lowcountry, Midlands and Pee Dee measuring high temperatures in the 80's. The NWS station at the Charleston International Airport recorded the seventh warmest November 1st in its 89-year period of record. By the middle of the month, the air mass center over New England extended southwest across the Carolinas and combined with the low-pressure system off the coast to create multiple cold air damming scenarios for the state. Widespread precipitation over the region overnight on November 23 and into the following morning produced a wintry mix in portions of the Upstate. Freezing rain coated trees in ice on Paris Mountain and reports of a little icing on trees and power lines were made from the Gaffney area. Under the wedge of cold air, temperatures in the Midlands held in the upper 40's to mid 50's, while along the coast temperatures were in the upper 60's to near 70 degrees in Charleston. The combination of strong, onshore winds and King Tides caused major coastal flooding along the coast at the end of the month. The tidal gauge at Charleston Harbor on November 24 reported a MLLW of 8.72 ft., the sixth highest tide recorded in Charleston since 1901, and it surpassed the historic flooding during the October 2015 event. The MLLW at the gauges at Oyster Landing and Springmaid Pier were both over eight feet, with readings of 8.3 ft. and 8.71 ft., respectively. Many media and social media outlets posted pictures of the saltwater flooding as it impacted coastal areas from Daufuskie Island to Myrtle Beach.

DECEMBER

After a rather cold November, December started with rather warm temperatures across the state and many locations reported high and low temperatures 10 degrees above normal. Despite a few cold outbreaks throughout the month, average temperatures were well above normal for this time of year. Toward mid-month, a strong front pushed through the Southeast, bringing considerably colder air into the region and setting up the scenario for an early season winter storm during the weekend of Saturday, December 8. Snowfall in the Upstate ranged from 2 to 12 inches and Sleet and freezing rain in portions of the Piedmont and Midlands. The total storm snowfall of 4.3 inches at the NWS Greenville-Spartanburg Office in Greer made it the second snowiest December on record since 1962. Multiple storm systems moved across the state during the month, producing excessive amounts of rainfall, up to 17 inches in some areas. December 2018 was the wettest on record for two of the longest operating NWS COOP stations in the state: 9.97 inches at Little Mountain (125 year record) and 9.92 inches at Newberry (113 year record). All remaining dryness that had lingered in portions of the Lowcountry and Central Savannah River Area were erased, and the state was drought-free going into the new year.

2018 ANNUAL PRECIPITATION (inches)

2018 ANNUAL TEMPERATURES (degrees F)