The 2017 New Year arrived on Sunday with a nearly stationary boundary separating cloudy, wet weather north of the Midlands to partly sunny, mild conditions to the south. Greenwood reported rain and 46 degrees while, it was partly sunny and 68 degrees on Hilton Head Island. On January 6, freezing air eased into the South Carolina Mountains. Caesars Head reported a morning low temperature of 27 degrees. Just after dark, an area of low pressure developed over the northern Gulf and began spreading snow into the Upstate. The Sandhill Experiment Station received 1.85 inches of rain. Travelers Rest measured a snow depth of 6.2 inches. Measurable snows extended to the Columbia Metro with a tenth of an inch. Snowflakes were observed as east and south as Charleston, and Lee counties. Cold air covered South Carolina on January 9. Chesterfield noted a minimum temperature of 13 degrees. There were no reported high temperatures reaching 50 degrees. Date record warmth was recorded on the afternoon of January 13 with Columbia Metro and Charleston Air Force Base at 80 degrees. On January 17, the first (EF2 rated) of two tornadoes affected northeast Barnwell County, and northern Bamberg County for a nearly fourteen-mile path. The second tornado (EF1 rated) passed near Cope in Orangeburg County. West winds on January 29, gusted to 38 mph at Columbia Metro Airport. Snow showers were observed before sunset and into the early evening at Caesars Head and Walhalla.
Sunny, warm weather was observed on February 1, with an afternoon high temperature of 75 degrees at Florence, and Charleston. On Thursday, it was a 76 degrees at Sumter and Beaufort. Light rainfall on Friday, February 3, fell along a southward-moving cold front from Aiken into Myrtle Beach. The Saturday early morning temperature fell to 20 degrees at Table Rock. Sandy Springs reported a morning temperature of 28 degrees on February 6. Summerville reached a mild 72 degree afternoon high temperature. Thundershowers on February 7 drifted east during the evening hours dropping 0.84 inches of rain in Anderson. A strong line of thunderstorms traveled across the state on February 9, bringing colder air and gusty west winds. Winds reached 42 mph at Charleston Air Force Base. A hard freeze on February 10, morning moved the temperature to 22 degrees at Rock Hill. Saturday saw a dramatic rebound back to 74 degrees at Allendale. On Sunday, February 12, the Greenville-Spartanburg Airport had low temperature of 61 degrees, and a date record high of 81 degrees. Frost was observed in the Low Country early on February 13. The Georgetown Airport reported a low temperature of 31 degrees. Warm air advanced over the state early on February 15 causing severe weather. Straight-line winds near Elko were estimated by a NWS storm survey team at 80 mph. Hailstones of 1.50 inches in diameter fell near Bonneau Beach. Low temperatures on February 16, fell to 27 degrees at Lake Greenwood. The high temperature at Lake City reached 78 degrees on February 20. Mostly sunny skies and light winds on February 24, allowed the mercury to move into the 80's. The afternoon high was was 81 degrees at McEntire Air National Guard Base. A cold front entered the Upstate during the afternoon of February 26. Winds gusted to 37 mph at the Greenville Downtown Airport.
Date record warmth (84 degrees) was observed on March 1 at Columbia Metro. Late afternoon storms developed over the Upstate, some with large hail. The USGS gage at Hickory Tavern in Laurens County received 0.43 inches of rain in the 15 minutes, and hailstones estimated to be two inches in diameter. A wind gust of 58 mph was recorded at the Greenville Downtown Airport. On the morning of March 4, the temperature was 22 degrees at the Walhalla Fish Hatchery. That afternoon the Charleston Air Force Base reported sunny skies, and 59 degrees. The mercury fell to 32 degrees at Summerville on Sunday morning, March 5. A few light showers were reported on March 6. Afternoon temperatures warmed to a mild 72 degrees at Columbia Metro Airport. The weather on March 7 was much the same with additional scattered showers and 75 degrees for Anderson. Sullivan's Island warmed to 79 degrees on March 8. Another and more potent boundary of colder air collided with the warmth early on the morning of March 10. Snow was reported at the Greenville-Spartanburg Airport on March 12. By daylight that Sunday, a mixture of snow and rain had progressed into the northern Midlands. Bands of moderate snow were observed over Chester and Lancaster counties. Pageland measured the heaviest snowfall amount with 3.75 inches. A heavy frost was observed on the morning March 13. Ninety Nine Islands reported a low temperature of 23 degrees. On March 15, Sassafras Mountain recorded a 12.4 degree low temperature. A hard freeze on March 16 was noted from a line north of and including Allendale, Walterboro, Manning, Kingstree and Conway. It was 17 degrees in Greenwood, and 21 degrees in Calhoun Falls. Preliminary inspections of berry and peach acreage indicated damage not seen since the late-season cold of April 8, 2007. On March 17, Summerville warmed from a 28-degree start to an afternoon high of 68 degrees. On the first day of spring, temperatures on March 20 fell to 28 degrees in Whitmire. Warming on March 21, the Charleston Air Force Base high temperature of 90 degrees tied the station's March record and was their warmest March day in 43 years. Severe storms produced 1.75-inch hail that covered the ground in Travelers Rest. 3.0-inch hail was observed 3 miles south-southwest of Greer. The McEntire Air National Guard Base Airport measured a wind gust of 58 mph. The Savannah River Site’s Area A Wind Tower recorded a gust of 81 mph. On March 30, a line of thunderstorms formed at mid-day from Jasper County northward into Cherokee County. Heavy rains caused flash flooding from downtown into Forest Acres. Instruments at the MLK Park in Five Points measured 2.20 inches of rain in 48 minutes.
Cooler air entered the state on the first day of April, moving the minimum temperature to 43 degrees at Sassafras Mountain. Thunderstorms on April 3 produced nine confirmed tornadoes. An EF-2 tornado near Cameron in Calhoun County destroyed storage buildings, barns and damaged homes. EF1-rated tornadoes affected portions of Pickens County near Central, property north of Whitmire and an area just south of Monetta. EF0 tornadoes were observed at Aiken, southwest of Berea, northwest of Laurens and Carlisle, and east of Gifford in Hampton County. Most of the paths were in rural settings with extensive tree and utility damage. Straight-line winds estimated at 88 mph damaged property in Edgefield with additional NWS storm surveys indicating 80 mph winds just south of Modoc in McCormick County and over parts of Lexington County near Gilbert. The USGS rain gage near Table Rock Reservoir received 1.76 inches of rain in two hours. Severe weather developed again on April 5. Golf ball-sized hail pelted Willington, Johnston, Lexington, Springdale and near Rembert. Winds of 68 mph were registered at the Columbia Metro Airport. An EF2 tornado raced 7 miles from just east of Johnston into Ward. An EF0 tornado caused localized damage northwest of Antreville in Anderson County and near Honea Path. Straight- line winds, estimated at 85 mph, roared through the south side of Hopkins. Instruments at the MLK Park in Five Points measured 1.73 inches of rain in just 20 minutes, part of a 3.50-inch total. Flash flooding caused a 15-minute rise in the Rocky Branch Creek of 5.64 feet to a stage of 11.47 feet. Clearing, blue skies on April 6 were accompanied with gusting west winds. The Florence Regional Airport recorded 51 mph gust. On April 18, a heavy thundershower of 1.91 inches soaked Blackville. One-inch diameter hail fell near Pritchardville. On April 23, low pressure over northern Alabama began drew heavy rain into South Carolina. Downpours produced flash flooding across the Midlands. The Anderson Airport reported heavy rain and 52 degrees. At the same time, the Beaufort Marine Corps Air Station noted clear skies and 77 degrees. Heavy rains continued on Monday April 24 with a 7:00 a.m. twenty-four hour measurement of 4.00 inches at Sullivan's Island. Waves of drenching rains fell through most of Monday from the Piedmont to the coast. A nearly stationary cluster of storms caused flash flooding in Rowesville and Elloree. Two Santee CoCoRaHS observers reported multi-day rains of 6.54 and 5.75 inches respectively. Andrews measured a two-day rainfall amount of 8.80 inches that closed roads.
Showers entered the Upstate on May 1, bringing rain and gusty winds. The line of storms intensified as they slowly marched across the state reaching the coastal counties overnight. Conditions deteriorated on May 4 as a squall line tracked over the Lowcountry, Midlands and Pee Dee. Three EF1-rated tornadoes were reported in Colleton County near Canadys, Hendersonville and Walterboro. Two EF1-rated tornadoes developed in Darlington County near Oates and Hartsville and one EF1-rated tornado developed near Holly Hill. There was also a confirmed report of an EF0-rated tornado near Patrick in Chesterfield County. Walhalla received rains of 2.65. On May 10, Columbia Metro and Orangeburg recorded afternoon highs of 93 degrees. There were public reports of nickel to dime-sized hail in Orangeburg and a funnel cloud was sighted near The Citadel in Charleston on May 14. After a cool morning on May 15, Pickens reported a high temperature of 89 degrees. A large frontal system approached the state on May 20, bringing thunderstorms and heavy rain. Anderson received an overnight accumulation of 4.45 inches. A stalled frontal boundary triggered thunderstorms on May 22. Stormy weather continued on May 23 with 5.23 inches of rain at Fort Johnson. The weather turned severe on May 23 with reports of hail, intense thunderstorms and three tornadoes. An EF-1 tornado began a 3-mile path in Saluda County with 110 mph peak estimated winds. An EF-2 tornado traveled 12 miles through northern Saluda and Newberry counties. An EF-1 tornado touched down northeast of Lancaster, close to the North Carolina state line. Severe weather impacted the state on May 29 as a mesoscale convective feature tracked across the Midlands with destructive wind gusts and large hail. The Columbia Metro airport recorded a 60-mph wind gust. 47-mph gusts were observed at both Lake Thurmond and the Columbia Owens Downtown Airport. Baseball-sized hail fell in Johnston and 2-inch hail fell along the Edgefield-Saluda county line.
Southwesterly winds ahead of a slow-moving cold front forced a high temperature of 94 degrees at USC in Columbia on the first day of June 2017. On June 3, an upper level trough triggered numerous Upstate rain showers and thunderstorms. One-inch hail was observed near Welcome with a wind gust estimated to be 60 mph. A decayed cold frontal boundary and diurnal heating forced another round of Upstate rain and thunderstorms on June 4. The Greer National Weather Service recorded 0.52 inches of rain. The USGS rain gage near Pageland captured 2.41 inches of rain. On June 5, Coastal dew point temperatures along the coast hovered in the 75-78. A stalled offshore frontal boundary on June 8 produced intermittent rain showers to the beaches. Sullivan’s Island reported a daily total of 2.22 inches. On June 12, numerous sites reported morning temperatures in the low 60's. June 14-15 saw widespread heat and increased humidity and afternoon storms. Both of Columbia's airports reported 96 degrees on June 15. Strong thunderstorms on June 15 dropped heavy rain across the state. McEntire Air National Guard Base collected 3.77 inches in 6 hours.
On the morning of June 19, the Beaufort Marine Corps Air Station observed a 7:00 a.m. temperature of 81 degrees and a dew point temperature of 77 degrees. Rain and thunderstorms affected the Midlands, Upstate, and Pee Dee on June 20. The Greenwood County Airport recorded 2.23 inches. Widespread rain and drizzle marked the Summer Solstice on June 21, and continued the next day. Moncks Corner saw 3.4 inches of rain on June 22. A weakening cold front stalled offshore on June 25 triggering afternoon rain and thunderstorms. Daufuskie Island reported receiving 1.62 inches between 3:10 and 4:00 p.m. Sunday's thunderstorm activity produced numerous reports of trees down in Beaufort and Jasper counties. On June 29, high pressure migrated offshore initiating a southwesterly flow of sub-tropical air over the state for a more typical summer temperature and humidity regime. A high temperature of 92 degrees was recorded at Lake City. With a humid, southwesterly flow at the surface, a weakening trough aloft triggered lines of convection that swept over the state on June 30. Precipitation ranged from light drizzle to heavy rain from strong thunderstorm cells.
The Bermuda High strengthened over the state yielding above normal summer temperatures, abundant humidity, and scattered afternoon thunderstorm activity for the start of July. Widespread afternoon thunderstorms developed binging periods of heavy rain throughout the state on July 3. An observer on Daufuskie Island measured 0.97 inches of rain that fell between 1:30-2:00 p.m. A weakening frontal boundary brought morning overcast on the 4th of July. Beginning July 5, the sub-tropical high built in from the east raising temperatures and dew points. On July 7, evening thunderstorms downed trees and produced one-inch hail in Aiken County and one and three-quarter inch hail in Sumter County. A cold front swept over the state on July 9 bringing slight relief from the week's high temperatures and humidity.
A weakening frontal boundary draped across the state triggered widespread afternoon thunderstorm activity on July 10. Counties from the Midlands to the coast received afternoon thunderstorms and rain. Santuck reported high temperature of 99 degrees on July 15. Strong afternoon thunderstorm produced heavy rains and damaging winds on July 15-16. The Marlboro County Jetport observed wind gusts of 58 mph. Walterboro reported a July 16 rainfall of 3.91 inches. Four people were injured by a lightning strike on the Isle of Palms.
July 17 began with a decaying stationary front draped over the South Carolina-North Carolina border. The National Weather Service office in Greer received a report of quarter-sized hail near Tigerville before 9 a.m. On July 18, 3.5 inches of heavy rain fell at the Florence airport. High pressure built in over the state bringing the warmest high temperatures of 2017 to date. Santuck recorded a 101 degree afternoon high temperatures on July 19 and July 21. MCAS Beaufort sweltered with a high temperature of 89 degrees. Slow moving storms produced torrential rainfall July 19. North Charleston reported 3.53 inches of rain. Hail, 1.00-1.25 inches in diameter, fell at several locations in Berkeley and Charleston Counties. A pre-frontal trough caused widespread strong convection across the Midlands on July 23. The National Weather Service office in Columbia reported 3.82 inches fell in one hour at the gage in MLK Park.
A surface trough on July 24 triggered late afternoon convection in the moist, unstable air over the Midlands. A CoCoRaHS volunteer in Gilbert observed 1.52 inches of afternoon rain in 40 minutes. Diurnal heating caused an outbreak of strong thunderstorms late Friday afternoon, July 28. There were dozens of reports of downed trees, power lines. The Anderson County Airport recorded a 51 mph wind gust, 0.36 inches of rain, and an afternoon high temperature of 91 degrees. The Columbia Metro Airport and MCAS Beaufort reached a temperature of 94 degrees on July 28.
The low temperature for the first day of August was 50 degrees at Jocassee. High pressure over the eastern U.S. weakened and shifted east late Wednesday, August 2, and brought a southwest flow of warm, humid air over the state along a coastal trough. A weak frontal boundary stalled over the Midlands on August 5. This feature triggered a wide swath of scattered afternoon thunderstorms along the I-20 corridor Saturday and Sunday. The Orangeburg Municipal Airport received 0.95 inches of rain in three hours on Sunday, August 6.
A frontal boundary sagged slowly south over the state on Tuesday, August 8, and was accompanied with imbedded thunderstorms. The cold front pushed offshore Wednesday morning and a surface low developed on the boundary offshore. This feature and abundant surface moisture created a swath of heavy rain across Aiken County eastwards to Horry County. The Walterboro reported 3.31 inches. The stalled offshore front triggered coastal thunderstorms on Thursday, August 10. A CoCoRaHS observer reported 4.16 inches of rain at Mt. Pleasant.
August 21, the day of the solar eclipse, a weak surface front along the coast triggered afternoon showers and thunderstorms. Numerous locations along the coast were unable to have an unobscured view of the total solar eclipse due to the coastal clouds and rain. Charleston Air Force Base reported light rain and a 6000 foot ceiling during Monday's solar eclipse. Elsewhere during the eclipse, the Anderson County Airport reported mostly cloudy skies and a 12,000 foot ceiling. The Columbia Metropolitan Airport observed mostly clear skies, and a temperature drop from 93 to 89 degrees. At the McEntire Air National Guard Base in Richland County, the temperature dropped from 92.7 degrees to an eclipse minimum of 80.6 degrees under mostly clear skies.
The last week of August 2017 began with a 56-degree low temperature at Jocassee. A deepening offshore low pressure system tracked northeast and became Potential Tropical Cyclone Ten on Sunday evening, August 27. PTC 10's offshore passage brought coastal rain showers and gusty winds. The Beaufort County Airport reported a peak gust of 37 mph on Monday afternoon. Sullivans Island had a 24-hour rainfall of 3.45 inches by Tuesday, August 29.
The remnant circulation of Hurricane Harvey merged with a cold front west of the state on Friday, September 1. The state's weekend high temperatures were 93 degrees at the Orangeburg 2 COOP site on Saturday, and 93 degrees at the Columbia Metro Airport on Sunday. High pressure dominated the state's weather with mostly clear skies and a southerly flow for the beginning of the week on September 4. A pre-frontal trough triggered Upstate, Pee-Dee and Low country rain and thunderstorms around midnight on Tuesday, September 5. McClellanville 7NE reported 2.29 inches of overnight rain. Trees and limbs were knocked down by thunderstorms in Barnwell and Kershaw counties. A cold front swept over the state on Wednesday, September 6. Lines of thunderstorms downed trees in Clarendon and Lee counties.
On Monday, September 11, the center of Tropical Storm Irma passed 200 miles southwest of the state. The storm's expansive eastern precipitation shield affected the entire state with periods of heavy rain and damaging tropical storm force winds on Monday and early Tuesday. The strongest winds and heaviest rainfall amounts were reported along the coast with widespread flooding due to storm surge, heavy surf, high tides and persistent easterly winds. The Charleston Air Force Base had the highest official maximum sustained wind of 43 miles per hour. The 10-meter high Folly Beach C-MAN site recorded 51 mph east winds gusting to 64 mph. A nearby non-NWS WeatherFlow instrument captured a gust of 72.5 mph. The Hilton Head Airport had a minimum sea level pressure of 999.7 millibars.
Strong winds blew down hundreds of trees across Beaufort, Charleston, Colleton, Dorchester, Hampton and Jasper counties that blocked roads and knocked out power lines. A weak, short-lived EF0 tornado touched down between Sullivan's Island and Mount Pleasant. The tornado was only 90 yards wide and on the ground for 0.57 miles. Tornadic damage was confined to downed tree limbs, uprooted trees and minor property damage.
The peak storm surge in Charleston was 4.87 feet and the peak storm tide was 9.92 feet above mean lower low water (MLLW). The storm tide was over four feet above normal and one of the highest surges since 1989's Hurricane Hugo. Many streets were flooded and impassable in Charleston. Dramatic images showed water cascading over the Battery and filling lower Charleston Peninsula streets to waist level.
Irma's outer rain bands dropped heavy rain along the coast that exacerbated storm surge and coastal surf flooding. During a period from 8:00 p.m. September 9 through 2 a.m. September 13, the Church Creek gage near West Ashley collected 8.97 inches of rainfall. 8.22 inches was collected inland at Youman's Farm in Hampton County during the same period. 6.26 inches or rain was reported by the Beaufort Marine Corp Air Station. A CoCoRaHS observer in Beaufort reported 9.07 inches of rain.
Conditions were less dire in Georgetown and Horry counties. The Myrtle Beach International Airport reported a peak wind gust of 54 mph and a 24-hour rainfall amount of 2.91 inches. The Georgetown County Airport had a peak gust of 61 mph from the northeast but a 24-hour rainfall total of 4.33 inches. Storm surge along the coast in Horry County was estimated to be 2.5 feet.
Away from the coast, the Holly Hill 1 SW COOP observer collected 6.57 inches of rain in 24 hours. Across the Midlands, rainfall amounts of 4.11 inches, 3.78 inches, and 2.52 inches were recorded at the Augusta Bush Airfield in Georgia, the Columbia Metro Airport, and the Florence Regional Airport, respectively. The Clemson-Oconee County Airport had the highest inland gust of 57.5 mph. The Columbia Metro Airport had a 51 mph gust.
The maximum temperature during Monday's tropical storm event was 78 degrees observed both at the North Myrtle Beach Airport and the Charleston Air Force Base. Clearing was rapid Tuesday afternoon after a lingering morning overcast. With Irma's remnant circulation well to the northwest, high pressure built in Wednesday, September 13, bringing cooler, drier air. Wednesday morning's low temperature was 53 degrees at Lake Greenwood under clear skies. Starting September 18, high pressure dominated the state's weather for the entire week. Monday's low temperature was 58 degrees at Table Rock. On September 20, the high temperature reached 97 degrees at Orangeburg. Hot and dry conditions continued on September 22 with high pressure firmly anchored over the state.
High pressure, above normal temperatures and very dry conditions persisted September 25-28. 99 degrees was the high temperature in Orangeburg on Thursday, September 28. A cold front stalled over the coast on Friday triggering coastal rain showers. A CoCoRaHS observer in Hanahan reported 1.78 inches of rainfall during a 24-hour period ending on the last day of September. A secondary cold front that Saturday, ushered in a cool, dry Canadian air mass for the start of October.
With the Canadian air mass firmly in place over the state, Sunday's morning low temperature was 42.6 degrees on Sassafras Mountain. Reports of morning low temperatures in the low to mid-50's were common across the Midlands and Pee Dee on October 1. Gusty northeast winds persisted during the day on Sunday. A broad ridge of high pressure fixed over the U.S. east coast kept warm and very dry conditions across the state through September 6.
Early on October 8, Hurricane Nate made landfall near Biloxi, Mississippi. The subtropical high steered the remnants of Nate northeast into the Ohio River Valley with an expansive cloud shield that covered the state. Embedded severe storm crossed over the Upstate and northern Midlands Sunday, October 8 and produced five tornadoes (see table below). The tornadoes produced widespread tree damage along their paths. Numerous homes and outbuildings were also damaged by the tornadoes. Despite persistent cloud cover Sunday, the Columbia Metro Airport observed a high temperature of 89 degrees. The Jocassee COOP observer reported a 24-hour rainfall amount of 7.05 inches attributable to the remnants of Hurricane Nate.
| Est. Start Time | Location/County | Max. Rating | Est. Max. Winds | Max. Width | Path Length | Inj. |
|---|---|---|---|---|---|---|
| 4:10 PM | Cross Hill/Laurens | EF2 | 120 mph | 100 yards | 38 miles | 1 |
| 4:20 PM | Chappels/Newberry | EF1 | 108 mph | 50 yards | 2.4 miles | 0 |
| 4:35 PM | Norris/Pickens | EF2 | 130 mph | 300 yards | 8.4 miles | 0 |
| 5:30 PM | Buffalo/Union | EF0 | 75 | 50 yards | 0.24 miles | 0 |
| 5:40 PM | Landrum/Spartanburg | EF1 | 95 | 200 yards | 1.5 miles | 0 |
On October 11, the Columbia Metro Airport reported a date record high minimum temperature of 77 degrees. With abundant surface moisture in place, numerous sites reported patchy, dense morning fog. On October 12, high temperature date records were set at Columbia Metro and tied at the Charleston Air Force Base with readings of 91 and 87 degrees, respectively. Late on October 12, a weak cold front passed over the state and produced Lowcountry thunderstorms after sunset.
A cold front passed over the state on Monday, October 16. The front triggered light rain showers. The Rock Hill Airport reported 0.43 inches of rain. Before the front reached the coast, the Beaufort Marine Corps Air Station recorded a high temperature of 89 degrees. High pressure built in over the state for the rest of the week. Cool, dry air settled in for pleasant fall weather. Crisp cool mornings, low humidity and clear skies persisted into the weekend. A CoCoRaHS station in Greer noted a light morning frost on October 18.
A strong cold front, associated with a rapidly deepening low pressure system over the Great Lakes, thundered over the state on October 23. Strong storms embedded in the frontal boundary produced heavy rain, strong winds, and four tornadoes over counties of the Upstate (see table below). Weather instruments on Sassafras Mountain recorded sustained winds of 35.6 mph with gusts to 55 mph. Sassafras Mountain also received the state's highest weekly rainfall total of 5.82 inches on October 23. Numerous Upstate COOP sites reported 24-hour rainfall amounts over four inches.
| Est. Start Time | Location/County | Max. Rating | Est. Max. Winds | Max. Width | Path Length | Inj. |
|---|---|---|---|---|---|---|
| 2:52 PM | Woodruff/Spartanburg | EF1 | 95 mph | 100 yards | 13.43 miles | 0 |
| 3:12 PM | Spartanburg/Spartanburg | EF2 | 120 mph | 350 yards | 3.05 miles | 1 |
| 3:36 PM | Gaffney/Cherokee | EF2 | 120 mph | 150 yards | 4.96 miles | 0 |
| 10:27 PM | Conway/Horry | EF1 | 95 | 95 yards | 0.6 miles | 0 |
A cold front passed over the state during the day on October 29. That day’s high temperature on Sassafras Mountain, 50.5 degrees, occurred at 12:30 a.m. Sassafras Mountain's low temperature, 26.1 degrees, was recorded at 10:28 p.m. that evening. On October 30, numerous sites observed morning temperatures at or below freezing. CoCoRaHS observers in Gaffney, Sumter, and Cope reported light frost. Sassafras Mountain recorded a low temperature of 25.7 degrees. Tuesday morning, October 31, the Cedar Creek had a morning low temperature of 28 degrees.
High pressure dominated the state's weather through Friday, November 3. Clear conditions and southwest winds contributed to unseasonably warm afternoon high temperatures in the 80s. Orangeburg observed a high temperature of 86 degrees on November 3. Patchy dense fog began the week's weather on Monday morning, November 6. Zero visibility was reported at airports in Laurens, Colleton, and Marlboro counties. After the fog cleared, high pressure and a southwesterly surface wind helped push afternoon temperatures into the mid-80s on Monday. The high temperature at the Charleston Air Force Base reached 82 degrees on November 6. An area of low pressure developed over the Upstate on November 9 and interacted with an offshore cold front. This offshore front provided abundant moisture for a day-long rain event. Thursday's rain totalled to 1.35 inches at Orangeburg. A cold front ahead of a large, cold, dry Canadian air mass passed over the state late November 10. Temperatures dropped rapidly behind the front. 27.5 degrees on Sassafras Mountain was the state's lowest temperature on November 11.
On Monday, November 13, a weakening cold front produced pre-dawn light rain and foggy conditions. Airports in Chester, Lancaster and York counties reported zero visibility in fog. Visibility at the Columbia Metro Airport dropped to a half mile under 200 foot ceilings. The airport also received 0.33 inches of pre-dawn rain. Skies cleared Monday afternoon and temperatures rose to 68 degrees at Orangeburg. Cool, dry Canadian high pressure moved over the state on November 14. Cedar Creek had a morning low temperature Tuesday of 34 degrees. On Thursday, November 16, a weak, dry, cold front dissipated over the state. Cedar Creek recorded another cold morning start of 29 degrees November 17 was another cool, clear day and the fourth consecutive day without any rain for the state as a ridge of high pressure dominated the state's weather. High pressure shifted east on November 18 and produced a warm, southwest surface wind. The Charleston Air Force Base warmed to 76 degrees. Instruments on Sassafras Mountain recorded 30 mph sustained winds gusting to 45.6 mph early Sunday morning, November 19. Airports in Columbia, Charleston, North Myrtle Beach and Florence all reported a Sunday afternoon high temperature of 67 degrees.
Monday morning, November 20, the low temperature at Whitmire was 23 degrees. CoCoRaHS observers in Myrtle Beach and Gaffney reported their first frost. On Tuesday, November 21, high pressure shifted slowly to the east after another cold morning. Cedar Creek reported a low temperature of 24 degrees. Late on Tuesday, November 21, a coastal trough produced rain showers and scattered thunderstorms. Observers in Bamberg and Barnwell counties reported 24-hour rainfall amounts of 0.93 and 1.01 inches, respectively. Northerly winds kept Thanksgiving Day temperatures more seasonable. Chesnee was 29 degrees Thursday morning and the Greenwood County Airport only reached 59 degrees under clear skies. Cool, dry, high pressure over the state produced cold mornings the last week of December. Ninety Nine Islands reported morning low temperature of 24 degrees on November 27.
Airports in Chester, Lancaster and Pickens counties reported morning visibilities reduced to zero miles in dense fog on the first day of December. The temperature warmed to 77 degrees at Cades. On December 2, an area of low pressure produced scattered light rain showers over northeast counties of the state. The Florence Regional Airport received 0.18 inches of rain. Cheraw had a high temperature of 74 degrees on December 3.
Monday, December 4, began with a 30-degree morning low temperature at Ninety Nine Islands. The Beaufort Marine Corps Air Station reported a visibility of a quarter mile under a 200-foot ceiling. Temperatures warmed to 71 degrees at Beaufort and Orangeburg under clear afternoon skies. Fog limited visibility to a quarter mile, and 200-foot cloud ceilings were reported at the airfields in Allendale and Manning on December 5. Mild temperatures persisted on December 6 before the cold front swept across the state late in the day. USC in Columbia and Darlington had afternoon high temperatures of 71 degrees. Rain for most of the state persisted on December 8. Florence had a 24-hour total rainfall of 2.62 inches. Columbia Metro had a high temperature of 45 degrees. North of the I-85 corridor, light snow began falling early Friday morning and continued until mid-day Saturday. Greenville Spartanburg Airport's 1.6 inches of snow was a date record 24-hour snowfall. Other 24-hour snowfall totals:
| Snowfall (in.) | |
|---|---|
| Caesars Head | 9.8 |
| Jocassee 8 WNW | 9.0 |
| Walhalla | 3.2 |
| Table Rock | 2.9 |
| Greenville-Spartanburg NWSFO | 1.6 |
| Travelers Rest 2 NE | 1.1 |
| Fountain Inn 2 SW | 0.5 |
| Woodruff | 0.3 |
Monday, December 11, began with the state under a dome of cold high pressure. Caesars Head had a 24-degree morning low temperature and reported 6 inches of snow remaining on the ground. A moisture-starved cold front swept over the state on Tuesday December 12. Frontal passage brought 23 mph winds, gusting 33 to mph, to the airport in Walterboro. Behind the cold front, cold air pushed the 32-degree isotherm to the coast Wednesday morning. The North Myrtle Beach Airport had a morning low temperature of 30 degrees and an afternoon high temperature of 49 degrees. High pressure centered over the Gulf coast channelled warm sub-tropical air over the state on Tuesday, December 19. Columbia Metro reported a high temperature of 79 degrees that tied a date record set in 1967.
A cold front passed over the state during the day on December 20. Numerous sites reported rainfall amounts over one inch. Orangeburg received 1.77 inches of rain. Winds turned to the southwest for the weekend ahead an approaching cold front. Barnwell warmed to 77 degrees on December 23. Charleston's Christmas Eve high temperature was 72 degrees. Christmas morning began at 23 degrees at Caesars Head, and under partly cloudy skies, the temperature reached 56 degrees at North Myrtle Beach. The weather observation station on Sassafras Mountain recorded 28 mph winds gusting to 43 mph as a dry cold front passed over the state on Christmas Day.
An offshore low pressure system on Wednesday, December 27, set produced light rain state-wide. The National Weather Service offices in Greer, Columbia and Charleston reported a high temperature of 50 degrees. Cold, dry Arctic high pressure built in over the state late Wednesday. Temperatures rebounded slightly on December 29 and into the weekend as dry conditions prevailed. Columbia reached 60 degrees Saturday after a morning low of 26 degrees. The low temperature on Sassafras Mountain plunged to 14.5 degrees to start December 31. Charleston's high temperature reached 49 degrees with 17 mph northeast winds gusting to 23 mph. The National Weather Service Office in Greer reported a trace of snowfall on the last day of 2017.
