On Monday, under cloudy skies, showers moved southwest from the coast. The Beaufort Marine Corps Air Station was the state's warmest site at 85 degrees. Manning measured one of the heavier rainfall amounts with 1.48 inches. Kingstree and Summerville made it to an unseasonably warm 88 degrees on Tuesday afternoon. Wednesday's 9:00 a.m. observation at Hilton Head indicated a fourteen-hour run of 100 percent relative humidity. Widely scattered showers developed through the day. Within the darkness of Thursday morning, a downpour in Spartanburg (3.58 inches reported on Thursday morning by a nearby CoCoRaHS volunteer) claimed the life of a motorist. September rainfall totals ended with a high value of 7.43 inches at Chesnee and a low value of 2.00 inches at Anderson AP. Heavy rains within the coastal zones began occurring before an unusual and dark Thursday sunrise which was obscured by the eastern horizon's thick cloudiness. 7:00 a.m. measurements included 2.75 inches at Georgetown AP and 2.24 inches in Darlington. Flooding rains in Charleston got into homes near the Charleston Landing. The 3.65 inches measured on the Charleston Peninsula caused lengthy road closures and detours. On Friday, steady and heavy rain, on a 60-knot low level jet stream, began to converge into an upper level area of "cut off" low pressure, located near the Georgia–Alabama border. A strong Hurricane Joaquin was near the Bahamas Islands. An axis of torrential rain developed over the Grand Strand around 3:00 p.m. At 6:53 p.m., the North Myrtle Beach AP reported a running day measurement of 6.53 inches with widespread flooding throughout Horry County. At 9:15 p.m., the USGS gage at Buck Creek near Longs had recorded a 24-hour total of 9.79 inches. A dam at Heather Lakes in Little River failed, requiring rescues. The first hours of Saturday began with a pipeline of intense heavy rain falling over the eastern half of South Carolina. Around 4:00 a.m., hard rain, in 60 to 70 mile-wide ribbons, was falling from Charleston through Columbia and Sumter, and into Greenville. A NWS employee reported 7.76 inches that had fallen at Mt. Pleasant. Knee-deep water within Charleston city limits brought traffic to a standstill. Other big rainfall numbers included two CWOP (Citizen Weather Observer Program) volunteers of 16.00 inches in Little River and 15.86 in N Myrtle Beach. Away from the coast, 5.95 inches fell at the Florence Regional AP and 5.85 inches was measured in Chesterfield. At 11:54 a.m., instruments at Springmaid Pier recorded east winds gusting at 46 mph and a near-time high tide of 8.30 feet which was 2.25 feet above the predicted value. Waist-deep water was observed on Johns Island. Saturated soils caused many mature trees to fall over in the breezy conditions. Weather satellite imagery on Saturday revealed a cyclonic feature over southern Georgia capturing Gulf Stream energy and the western-most periphery of the distant hurricane. During the evening hours, east winds gusted to 60 mph in the Charleston Harbor and 53 mph at Sullivan's Island. At 9:00 p.m., NWS instruments at Lake Moultrie indicated a minimum barometric pressure value of 29.49 inches of mercury. Wind-driven waves on elevated tides broke against and over the Charleston City southeast battery. At the midnight hour of October 3, Charleston AP had recorded 11.50 inches of rain and its greatest calendar-day total in recordkeeping, beginning 1938, and the most October rainfall of record in just 3 short days. Well before sunrise on Sunday, record and deadly rains expanded into Berkeley, Dorchester, Clarendon, Orangeburg, Williamsburg, Florence, Sumter, Kershaw, Richland and Lexington counties with rainfalls of 10 inches or higher. Daylight revealed fast-moving water from roadside ditches into neighborhood creeks and streams, topping spillways into the larger lakes. At 7:00 a.m., a Richland County Emergency Services rain gage at Gills Creek had recorded a staggering 12.68 inches of rain since midnight. At noon, 15.51 inches had fallen. Not even the oldest of inhabitants had ever witnessed such an event. Dams along the Arcadia Lakes basin began failing. Gills Creek swelled to 17.08 feet before the gage was destroyed. Extreme flooding and catastrophic property losses affected a four-mile stretch from Dentsville through the Lake Katharine community and downstream into the business section of Garners Ferry Road. Tense water rescues were performed in Columbia and along nearby river basins by multiple agencies and swift water specialist. Portions of Interstate 95, Interstate 20, Interstate 26 and the Interstate 77 bypass were closed due to high water. Urban and rural washouts of roadbeds were reported over all adjacent counties. The Columbia AP 24-hour rainfall of 8.74 inches established an all time record for any month. Hurried emergency responders performed every hour of the day despite downpours and interruption threats from additional breaches in dams. The Congaree River at Columbia reached a peak and "major flood" stage of 31.81 feet at 6:45 p.m. on Sunday, with a calculated flow of 185,000 cubic feet per second. Georgetown's 12.32-inch total for Saturday and Sunday turned the county into a lake. Over a foot of rain fell on Kingstree, surrounding it with rising water. Measurements at Mt Pleasant had reached a three-day accumulation of 24.23 inches. The day closed with many of the state's citizens experiencing restrictions to travel, overnight curfews and widespread losses of water and electricity. Confirmed vehicle-related drownings had risen to 4, some were missing. If that was not enough, the unstoppable rain kept falling. The state average temperature for the seven-day period was one degree above the long-term average.
The highest official temperature reported was 89 degrees at Andrews on September 29. The lowest official temperature reported was 49 degrees at Sassafras Mountain on October 3. *The heaviest “official” 24-hour rainfall reported was 12.83 inches at the USGS Black River gage in Kingstree on October 4. The state average rainfall for the seven-day period was 9.0 inches.
| Weekly | Jan 1 | Departure | |
|---|---|---|---|
| Anderson AP | 4.63 | 31.98 | -1.8 |
| Greer AP | 6.67 | 37.40 | 1.0 |
| Charlotte, NC AP | 3.71 | 28.27 | -4.0 |
| Columbia Metro AP | 11.10 | 48.18 | 12.3 |
| Orangeburg AP | 10.31 | 42.29 | 4.6 |
| Augusta, GA Bush AP | 1.97 | 32.30 | -2.3 |
| Florence AP | 10.79 | 40.78 | 6.2 |
| N Myrtle Beach AP | 13.99 | 52.04 | 9.8 |
| Charleston AP | 17.70 | 61.83 | 19.4 |
| Savannah, GA AP | 2.12 | 40.43 | 0.8 |
Weekly rainfall totals ending midnight Sunday.
4-inch depth soil temperature: Columbia 68 degrees, Charleston 74 degrees.
South Carolina river stages were near normal or in flood. Charleston Harbor reported a water temperature of 77 degrees and Springmaid Pier at Myrtle Beach reported a surf water temperature of 74 degrees.
**Due to multiple gages being destroyed or damaged by floodwaters, all rainfall amounts should be considered preliminary at this time.