Virginia · Mosquito Season Guide

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II. Virginia Mosquito Season Month by month

Virginia spans five physiographic regions, and mosquito season stretches accordingly. The coastal Tidewater — Hampton Roads, Virginia Beach, the Eastern Shore — runs from April into October, one of the longest seasons on the Eastern Seaboard. Northern Virginia's suburbs are among the fastest-growing Asian tiger mosquito habitats in the country. The mountains stay calm by comparison.

Very Low Low Moderate High Very High taller = more active · color = severity

Chart reflects central Virginia / Richmond baseline. Coastal Tidewater (Virginia Beach, Norfolk, Chesapeake) starts 3–4 weeks earlier and ends later. Mountain counties (Roanoke, Shenandoah Valley) peak shorter and lower.

~60

mosquito species recorded in Virginia

Apr–Oct

active season along the Tidewater coast — one of the longest in the mid-Atlantic

disease threats monitored annually: West Nile virus and Eastern equine encephalitis

counties and independent cities — all with VDH vector surveillance

Hampton Roads and the Tidewater: Virginia's long-season zone

The Hampton Roads metro — Virginia Beach, Norfolk, Chesapeake, Hampton, Newport News, Suffolk — sits at the intersection of the Chesapeake Bay, the Atlantic Ocean, and extensive tidal wetlands. The coastal plain's warm temperatures, humidity, and vast marsh habitat create one of the longest mosquito seasons on the Eastern Seaboard, regularly starting in April and running into October. The Great Dismal Swamp along the Virginia–North Carolina border is a particularly productive breeding zone for multiple species. Virginia Beach and Chesapeake have been among the highest-burden localities for WNV in the state in recent years.

Northern Virginia and the Asian tiger mosquito surge

Northern Virginia — Arlington, Fairfax, Prince William, Loudoun counties — is the fastest-growing Aedes albopictus hotspot in the state. The combination of dense suburban housing with lots of containers, regular rainfall, and the urban heat island effect creates ideal tiger mosquito habitat. The transition from a nuisance species to a genuine baseline problem happened rapidly in the 2010s: residents who remembered infrequent mosquito encounters now deal with aggressive daytime biting from April through October. The Asian tiger mosquito is now the dominant species encountered in most Northern Virginia yards during daylight hours.

EEE in Virginia's forested wetlands

EEE is detected in Virginia surveillance most seasons, particularly in the coastal plain and Piedmont areas with forested freshwater swamps. Localities including the Northern Neck, Middle Peninsula, and parts of southeastern Virginia have reported positive mosquito pools and horse cases in recent seasons. The Virginia Department of Health (VDH) publishes weekly Arboviral disease updates from June through October; residents near wooded wetlands should monitor these during peak season.

III. Virginia's Three Species to Know

Culex quinquefasciatus

Southern House Mosquito · ⚠ West Nile Vector

The dominant WNV vector along the Virginia coast and in the warmer Piedmont. Virginia sits in the transition zone between the Northern house mosquito (Cx. pipiens) and the Southern house mosquito (Cx. quinquefasciatus); both species are present, with the Southern species dominating in Hampton Roads and coastal localities. Both breed in stagnant water — storm drains, standing containers, catch basins — and feed at dusk and overnight. WNV is detected in Virginia Beach, Norfolk, Chesapeake, and Richmond surveillance pools most seasons.

Aedes albopictus

Asian Tiger Mosquito

Well established across all of Virginia east of the Blue Ridge, and the dominant nuisance species in Northern Virginia, Richmond, and Hampton Roads suburban areas. Visually distinctive: black with bold white stripes, aggressive daytime biter. Most active in the morning and late afternoon — catching residents off guard who are accustomed to evening-only mosquito pressure. Breeds in tiny container volumes. The single most effective thing Virginia residents can do is eliminate all standing water in their yard weekly; even a bottle cap is sufficient.

Aedes vexans

Inland Floodwater Mosquito

The most abundant mosquito in rural Virginia and a significant contributor to post-storm biting statewide. Eggs survive dry conditions in low-lying terrain for years, hatching en masse within days of flooding. Aggressive daytime biter; populations along the James, Rappahannock, Potomac, and New river corridors spike noticeably after summer thunderstorms. Not a major disease vector, but responsible for the worst post-storm nuisance biting experienced by outdoor workers, hikers, and suburban residents across central and western Virginia.

WNV is detected in Virginia surveillance traps every season. Coastal and Piedmont localities see the highest burden. EEE is also detected most seasons — particularly near forested freshwater wetlands in the coastal plain. Check current VDH Arboviral Disease reports →

IV. City-by-City Reference

City	Active Season	Off-Season	Notes	Live data
Richmond	Apr – Oct	Near-zero Nov–Mar	James River corridor amplifies floodwater species after storms; Cx. quinquefasciatus and Ae. albopictus both well established; WNV detected in Chesterfield/Henrico surveillance most seasons; urban density favors container breeders; season slightly shorter than Hampton Roads but longer than northern VA	Check live
Virginia Beach	Apr – Oct	Off Nov–Mar	Longest season in VA; Back Bay NWR and Chesapeake Bay coastal wetlands create extensive habitat; WNV detected regularly; Great Dismal Swamp on southern boundary; Cx. quinquefasciatus dominant at dusk; Ae. albopictus intense in residential areas; tourism season overlaps exactly with peak mosquito pressure	Check live
Norfolk	Apr – Oct	Off Nov–Mar	Hampton Roads harbor; low-lying urban terrain with extensive water infrastructure; WNV surveillance positive most seasons; Cx. quinquefasciatus and Ae. albopictus dominant; Navy installations run active vector control; tidal flooding events can trigger floodwater hatching events	Check live
Arlington	Apr – Oct	Off Nov–Mar	Northern Virginia suburb; Ae. albopictus is the dominant species — daytime biting April through October; Potomac River corridor; dense suburban landscaping with containers; WNV risk lower than coastal VA but present; season extends longer due to urban heat island; one of the most tiger-mosquito-dense areas in the state	Check live
Chesapeake	Apr – Oct	Off Nov–Mar	Great Dismal Swamp on its southern edge — one of the most productive mosquito habitats on the East Coast; among the highest WNV burden cities in the state; extensive agricultural ditches and wetlands; Cx. quinquefasciatus and Ae. albopictus both significant; EEE-positive pools detected in swamp fringe zones	Check live
Roanoke	May – Sep	Off Oct–Apr	Blue Ridge foothills — shorter season than coastal VA (3–4 weeks); lower overall peak; Roanoke River corridor amplifies floodwater species; Ae. albopictus present but less dense than Eastern VA; WNV detected but human case rate historically lower than Tidewater; mountain terrain limits marsh habitat	Check live
Charlottesville	May – Sep	Off Oct–Apr	Piedmont foothills; Rivanna River corridor; Ae. albopictus well established in residential areas; University of Virginia grounds have significant container and tree-hole breeding; season slightly shorter than Richmond; WNV detected in Albemarle County surveillance traps; EEE risk lower than coastal plain	Check live

More State Guides

Florida Year-round activity in the south — 80+ species including invasive Ae. aegypti and the Asian tiger mosquito across all 67 counties Texas ~85 species across four climate zones — Gulf Coast active March through November, with year-round pressure in the Rio Grande Valley California Central Valley is the #1 West Nile corridor in the US — invasive Ae. aegypti and Ae. albopictus now established in 20+ counties Georgia Atlanta metro leads the Southeast in Asian tiger mosquito density — active statewide March through November New York Ground zero for West Nile in the US (1999 Queens outbreak) — NYC metro and Long Island see the highest Northeast seasonal pressure Illinois Home of the 2002 Cook County West Nile outbreak — the deadliest urban WNV event in US history — peak season June through September Ohio Lake Erie to the Ohio River — WNV active in Franklin and Cuyahoga counties, with floodwater species surging after summer storms Pennsylvania Philadelphia WNV corridor meets rural EEE risk in western PA — the densest human population in the mid-Atlantic mosquito belt Michigan Site of the 2019 EEE outbreak — the deadliest in decades — 10 human cases and 6 deaths concentrated in SW Michigan Great Lakes wetlands New Jersey Oldest organized county mosquito control in the US (1914) — Pine Barrens EEE corridor and fierce salt marsh Shore species North Carolina The coastal plain runs one of the longest seasons in the Southeast — NC leads the nation in La Crosse encephalitis cases from the Appalachian foothills Maryland Chesapeake Bay watershed creates extraordinary mosquito habitat — tidal marshes, Eastern Shore wetlands, and the DC-Baltimore corridor combine for dense seasonal pressure Tennessee Memphis and the Mississippi River corridor historically record the highest WNV case counts in the mid-South — Ae. albopictus has colonized all 95 counties Indiana Indiana sits at the crossroads of the Great Lakes EEE belt — Lake Michigan wetlands in the north and the Wabash River floodplain drive intense seasonal pressure Louisiana The Gulf Coast's most intense pressure — coastal marshes and summer rains keep Cx. quinquefasciatus and Ae. aegypti active from March through November Alabama Mobile Bay to the Tennessee Valley — Ae. albopictus has reached all 67 counties and peak WNV season runs June through September South Carolina Low Country marshes produce some of the Southeast's densest Anopheles and Culex populations — season runs March through November Minnesota 10,000 lakes means 10,000 breeding sites — the Northwoods sees intense but short July–August peaks, while the Twin Cities face a longer June–September window Wisconsin Great Lakes wetlands and the Mississippi River backwaters drive strong WNV pressure in the Milwaukee corridor — peak season July through August Missouri At the confluence of the Missouri and Mississippi rivers — St. Louis historically ranks among the highest WNV cities in the US — season May through October Arkansas Delta rice-field flooding and the Arkansas River bottomlands create some of the highest rural mosquito pressure in the mid-South — active April through October Washington Western WA stays mild and damp year-round; the Yakima Valley and Columbia Basin face the highest WNV risk in the Pacific Northwest — peak July through September Arizona Monsoon season (July–September) drives sudden mosquito explosions across the Valley of the Sun — WNV detected annually Colorado Front Range WNV corridor stretches Denver to Fort Collins — eastern plains carry the state's highest risk Connecticut Connecticut River valley WNV pressure meets EEE risk in inland freshwater wetlands — active May through October Delaware Chesapeake and Delaware Bay marshes create outsized pressure for the nation's second-smallest state Hawaii Year-round activity at sea level — no native species, but Ae. aegypti and tiger mosquitoes established statewide Idaho Snake River Plain irrigation districts fuel summer WNV pressure — season June through September Iowa Mississippi River corridor and prairie wetlands drive intense June–September pressure — WNV active statewide Kansas Great Plains WNV corridor — Wichita and Kansas City see peak pressure July–August; floodwater species surge after storms Kentucky Ohio River corridor and Kentucky Lake wetlands sustain a long April–October season across all 120 counties Maine Short but intense July–August season — EEE detected in some years in the southern coastal plain Massachusetts EEE fatality rate exceeds 30% — the Plymouth County swamp complex is the active epicenter — season May through October Mississippi Gulf Coast near-year-round pressure meets Delta rice-field flooding for one of the South's most intense mosquito environments Montana Yellowstone and Missouri River corridors drive a compressed June–August season — WNV detected most years in eastern MT Nebraska Platte River valley and eastern Nebraska are among the Great Plains' most active WNV zones — peak July–August Nevada Las Vegas monsoon season drives July–September activity; Reno irrigation districts fuel a parallel northern peak New Hampshire EEE detected most years — the southern lakes and coastal plain are in the active Northeast EEE corridor New Mexico Monsoon season (July–September) creates sudden breeding habitat; WNV circulates in the Rio Grande valley annually North Dakota Red River Valley flooding produces some of the Great Plains' most extreme floodwater mosquito events — peak June–August Oklahoma One of the South-Central's most intense seasons — the Arkansas and Red River corridors sustain populations April through October Oregon Eastern Oregon Columbia Basin is the state's WNV hotspot; western Oregon runs a mild coastal season June through September Rhode Island New England's densest coastal pressure — Narragansett Bay salt marshes and WNV active in all five counties South Dakota Missouri River and James River valleys drive summer WNV activity — eastern SD sees the most intense pressure Utah Salt Lake Valley WNV corridor and irrigation districts sustain a July–September peak — drier areas see limited activity Vermont Champlain Valley runs Vermont's longest season — EEE detected in the Lake Champlain lowlands in some years West Virginia Kanawha and Ohio River valleys sustain a May–October season — Ae. albopictus now established statewide Wyoming The shortest meaningful season of any contiguous US state — North Platte valley WNV window is just 6–8 weeks

West Nile, dengue, and EEE: US disease risk by region → Asian tiger mosquitoes: why you're getting bitten during the day → Eliminating standing water: the highest-leverage yard move →