Today's Mosquito Risk in South Carolina: Real-Time Forecast & Activity Map
Check your ZIP code for local mosquito activity, West Nile risk, and prevention insights.
Built from CDC and NOAA data
Mosquito Surveillance Insights
- Annual WNV Cases
- about 30 to 60 confirmed cases annually
- Based on CDC ArboNET surveillance data
- Risk Tier
- Tier 3: Moderate
- Subtropical Lowcountry humidity sustains year-round biting in the southernmost counties.
- Per mosquito-risk-model regional tier
- Highest-Risk Areas
- Charleston, Richland, Greenville (WNV); Florence and Marion (Pee Dee EEE)
Current Situation in South Carolina
South Carolina runs warm and wet, with mosquito pressure built around the Lowcountry salt marsh, the Pee Dee freshwater swamps, and the Piedmont metros through Columbia and Greenville. WNV burden lands at roughly 30 to 60 confirmed human cases annually. Aedes aegypti is present along the southern coast around Charleston and Hilton Head, and Aedes albopictus is established statewide. The Pee Dee region in the northeast holds the state's most consistent EEE risk, tied to freshwater cypress swamps. Cx. quinquefasciatus dominates Culex transmission. The subtropical Lowcountry humidity sustains some of the longest biting seasons in the Southeast outside Florida. Biting season runs April through October.
Snapshot of the current mosquito situation in South Carolina, drawn from CDC ArboNET surveillance and the regional risk model.
- Risk Level
- Moderate
- Peak Activity
- April through October
- Dominant Vector
- Asian Tiger Mosquito (Aedes albopictus) statewide; Southern House Mosquito (Culex quinquefasciatus)
Where Mosquitoes Breed in South Carolina
South Carolina mosquito habitat splits between Lowcountry salt marsh, Pee Dee freshwater swamps, and the urban Piedmont. Salt marsh from Hilton Head through Charleston and up to the ACE Basin produces dense Aedes sollicitans and Aedes taeniorhynchus hatches. The Santee River swamps, Francis Marion National Forest, and the Pee Dee River bottomlands sustain Culiseta melanura tied to EEE bridge cycling. The Congaree floodplain south of Columbia produces sustained Aedes vexans hatches. Storm drains and tire piles across Charleston, Columbia, Greenville, and Myrtle Beach carry the urban Aedes albopictus and Cx. quinquefasciatus load.
Hotspot Counties & Areas
- Charleston County (Charleston, Lowcountry salt marsh)
- Richland County (Columbia, Congaree floodplain)
- Greenville County (Greenville, Piedmont metro)
- Horry County (Myrtle Beach, Grand Strand coast)
- Beaufort County (Hilton Head, ACE Basin)
- Florence and Marion counties (Pee Dee EEE focus)
- Francis Marion National Forest
- Congaree National Park bottomlands
Seasonal Activity Pattern
Biting starts in early April in the Lowcountry, peaks late July through September, and tapers through October with stragglers into November in Charleston and Hilton Head. WNV cases concentrate in August across Columbia and the Piedmont metros. EEE risk in the Pee Dee and Lowcountry swamps peaks late August through October. Salt-marsh biting around Hilton Head and the ACE Basin spikes hard around full-moon high tides. Aedes albopictus daytime biting in Lowcountry yards runs heavy from May through October. Heavy summer storms produce floodwater Aedes pulses along the Santee and Pee Dee.
Monthly Biting Intensity (Southeast)
South Carolina Mosquito Risk Profile
- WNV burden level
- Moderate
- about 30 to 60 confirmed cases annually
- EEE risk
- Documented in Pee Dee and Lowcountry
- Peak biting season
- April through October
- Top urban risk areas
- Charleston (Charleston)
- Columbia (Richland)
- Greenville (Greenville)
- Myrtle Beach (Horry)
Signature habitat: Lowcountry salt marsh, Santee River swamps, Pee Dee floodplains.
Climate driver: Subtropical Lowcountry humidity sustains year-round biting in the southernmost counties.
Check Your Local Mosquito Risk
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Common Mosquitoes in South Carolina
Understanding which mosquitoes are active in South Carolina helps you identify threats and take appropriate precautions. Click any card for details.
Asian Tiger Mosquito
Aedes albopictus
Risk: Eastern Equine Encephalitis, dengue, chikungunya, Zika, dog heartworm.
Key feature: A single bright white stripe down the center of the back.
Active: Spring through first hard frost. Eggs overwinter in cold climates and hatch when flooded by spring rain.
Southern House Mosquito
Culex quinquefasciatus
Risk: West Nile virus, St. Louis encephalitis, dog heartworm.
Key feature: Medium brown body with banded abdominal segments and no leg stripes.
Active: Year-round in the deep South; summer peak elsewhere. Most active from dusk through the first few hours after sunset.
Yellow Fever Mosquito
Aedes aegypti
Risk: Zika, dengue, yellow fever, chikungunya.
Key feature: Black body with white lyre-shaped markings on the thorax.
Active: Year-round in southern Florida and the Gulf; summer-only further north.
Eastern Equine Encephalitis
Vector: Asian Tiger Mosquito
Eastern Equine Encephalitis
Rare but devastating, with roughly 30% case fatality. Concentrated in Northeast swamp areas and the Gulf Coast.
What to watch for
- Onset typically 2 to 15 days after a bite
- Most cases mild or asymptomatic, small fraction severe
- Neurological signs (severe headache, neck stiffness, confusion) need ER care
Breaking the Cycle in South Carolina
The mosquito lifecycle takes about a week. These habits cut local biting pressure faster than anything else, building multiple layers of protection.
Drain the Yard Weekly
Empty buckets, planter saucers, kiddie pools, tarps, and clogged gutters. A week of standing water is one full mosquito generation.
Repel Before Going Out
EPA-registered DEET (20-30%), picaridin (20%), IR3535, or oil of lemon eucalyptus. Apply before going outside, especially at dusk and dawn.
Seal the House
Window and door screens with no tears. AC and porch fans both work. Mosquitoes struggle to fly upwind even at 1-2 mph air speed.
Treat Outdoor Clothing
Permethrin-treated long sleeves and pants for evening yard work, hiking, or fishing. Remains effective through 70+ wash cycles.
If You Develop Symptoms
Most mosquito bites are harmless. A small fraction can transmit illness, and knowing the timeline matters more than panicking at every itch.Five things to know.
Watch for fever
Fever, body aches, headache, or fatigue 2 to 15 days after a bite. West Nile often feels like flu, and most infections never get diagnosed.
Note where and when
A rough record of where and when you got bitten helps your doctor decide what to test for. Date, location, mosquito-heavy areas you visited.
Get help fast for neuro signs
Severe headache, neck stiffness, confusion, vision changes, or sudden muscle weakness can mean neuroinvasive WNV or EEE. Both are medical emergencies.
Pregnant exposure?
If pregnant and bitten in an area with documented Zika or local dengue transmission, mention to your OB. Same goes for travel exposure.
Children and seniors
Higher risk of severe disease from WNV, EEE, and dengue in adults over 60 and children under 5. Early call to the pediatrician or PCP if symptoms appear.
When does mosquito season end in South Carolina?
Mosquito activity winds down after the first hard freeze, which in South Carolina typically arrives around Nov 12. See the local first-frost window and city-by-city freeze dates.
South Carolina first frost datesAlso worried about ticks in South Carolina?
Lyme disease risk and tick activity track different seasonal patterns than mosquitoes. See your South Carolina tick forecast.
View South Carolina tick forecastStay Safe in South Carolina
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