Today's Mosquito Risk in Vermont: 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 2 to 5 confirmed cases annually
- Based on CDC ArboNET surveillance data
- Risk Tier
- Tier 4: Low
- Cool short summers limit population buildup; Lake Champlain corridor is the warmest zone.
- Per mosquito-risk-model regional tier
- Highest-Risk Areas
- Chittenden (Lake Champlain basin)
Current Situation in Vermont
Vermont is the lowest-pressure mosquito state in the Northeast, with cool short summers that limit population buildup statewide. WNV burden runs 2 to 5 confirmed human cases in a typical year, and EEE is rare. The warmest corridor is the Lake Champlain basin in Chittenden County, where Burlington summers stretch long enough to sustain meaningful Cx. pipiens activity. The Green Mountains and Northeast Kingdom stay cool, with mosquito pressure dominated by floodwater Aedes off beaver ponds and snowmelt rather than disease vectors. Aedes albopictus presence is limited so far. Biting season runs June through September, with peak activity in July.
Snapshot of the current mosquito situation in Vermont, drawn from CDC ArboNET surveillance and the regional risk model.
- Risk Level
- Minimal
- Peak Activity
- June through September
- Dominant Vector
- Northern House Mosquito (Culex pipiens)
Where Mosquitoes Breed in Vermont
Vermont mosquito habitat centers on Lake Champlain and the wetland complexes feeding it: Missisquoi Bay, the Champlain Islands, and the Winooski River delta. These produce sustained Cx. pipiens and Aedes vexans populations through summer. The Green Mountain valleys and Connecticut River bottomlands hold big floodwater Aedes hatches after spring snowmelt and summer storms. Beaver ponds across the Northeast Kingdom produce dense forest mosquito populations that punish hikers in early summer. Storm drains in Burlington, Rutland, and Montpelier carry the modest urban Culex load.
Hotspot Counties & Areas
- Chittenden County (Burlington, Lake Champlain shoreline)
- Champlain Islands (Grand Isle County)
- Washington County (Montpelier, central wetlands)
- Rutland County (Otter Creek floodplain)
- Connecticut River Valley (Windsor and Windham counties)
- Green Mountain National Forest beaver ponds
- Mount Mansfield and Stowe area trails
Seasonal Activity Pattern
Biting starts in early to mid June after snowmelt drives the first floodwater Aedes hatch, peaks in July, and fades through September. WNV transmission, when it happens, lands in August in the Lake Champlain corridor. The Green Mountain valleys see a sharp early-season spike from beaver-pond Aedes that tapers by early August. Mount Mansfield and high-elevation trails stay buggy well into July thanks to slow snowmelt.
Monthly Biting Intensity (Northeast)
Vermont Mosquito Risk Profile
- WNV burden level
- Minimal
- about 2 to 5 confirmed cases annually
- EEE risk
- Rare
- Peak biting season
- June through September
- Top urban risk areas
- Burlington (Chittenden)
- Rutland (Rutland)
- Montpelier (Washington)
Signature habitat: Lake Champlain wetlands, Green Mountain valleys, beaver ponds.
Climate driver: Cool short summers limit population buildup; Lake Champlain corridor is the warmest zone.
Check Your Local Mosquito Risk
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Common Mosquitoes in Vermont
Understanding which mosquitoes are active in Vermont helps you identify threats and take appropriate precautions. Click any card for details.
Northern House Mosquito
Culex pipiens
Risk: West Nile virus, St. Louis encephalitis, dog heartworm.
Key feature: Medium brown body with banded abdomen. Looks nearly identical to Cx. quinquefasciatus.
Active: Late spring through early fall in the north. Adult females overwinter in basements, garages, and storm drains.
Inland Floodwater Mosquito
Aedes vexans
Risk: Aggressive nuisance biter. Weak vector for West Nile, dog heartworm.
Key feature: Brown body with pale bands on the legs and a tapered abdomen.
Active: Spring through fall. Population spikes a week or two after major rain events.
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.
West Nile Virus
Vector: Northern House Mosquito
West Nile Virus
The dominant West Nile vector across the northern half of the US. About 80% of infections are asymptomatic.
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 Vermont
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.
Heading to a lake in Vermont?
Live water temperatures and swim conditions for Lake Champlain.
See Vermont lake temperaturesWhen does mosquito season end in Vermont?
Mosquito activity winds down after the first hard freeze, which in Vermont typically arrives around Sep 24. See the local first-frost window and city-by-city freeze dates.
Vermont first frost datesAlso worried about ticks in Vermont?
Lyme disease risk and tick activity track different seasonal patterns than mosquitoes. See your Vermont tick forecast.
View Vermont tick forecastStay Safe in Vermont
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