Today's Mosquito Risk in Maine: 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 5 confirmed cases annually
- Based on CDC ArboNET surveillance data
- Risk Tier
- Tier 4: Low
- Cool maritime climate compresses biting season; warming trend extending it.
- Per mosquito-risk-model regional tier
- Highest-Risk Areas
- York and Cumberland (coastal southern Maine)
Current Situation in Maine
Maine sits at the cool northeastern edge of the U.S. mosquito map, where a long maritime coast and 17 million acres of forest set the terms for the season. West Nile burden stays minimal, with roughly 5 confirmed human cases in a typical year, and EEE is rare but documented in southern swamp counties. Aedes aegypti has not established here, but Aedes albopictus is creeping north along the I-95 corridor as winters soften. The dominant biter is Culex pipiens in storm drains and inland swamps, with floodwater Aedes species hatching off snowmelt and summer rains. Biting season runs June through September, compressed by cool spring temperatures and clipped by the first October frost.
Snapshot of the current mosquito situation in Maine, 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 Maine
Maine mosquito habitat splits between the Acadia coastline and the deep inland forest. Salt marsh from Kittery up through York and Cumberland counties produces Aedes sollicitans, the painful saltmarsh biter that drifts inland on coastal breezes. Inland, the forested swamps and beaver ponds of Penobscot, Piscataquis, and Aroostook counties produce huge Aedes vexans hatches after spring snowmelt. Lake Sebago, the Penobscot River corridor, and Mount Desert Island all hold steady summer populations. Storm drains and roadside ditches in Portland, Bangor, and Lewiston carry the urban Cx. pipiens load.
Hotspot Counties & Areas
- Cumberland County (Portland metro)
- York County (highest population density, coastal salt marsh)
- Penobscot County (Bangor, inland swamps)
- Hancock County (Acadia National Park, Mount Desert Island)
- Androscoggin County (Lewiston, Auburn)
- Sebago Lake region
- Kennebec River Valley
Seasonal Activity Pattern
Mosquito biting starts in early June once nights hold above 50 degrees, peaks in July, and tapers through September. WNV transmission concentrates in August when Cx. pipiens populations crest in southern metros. Spring snowmelt produces a 2 to 3 week floodwater Aedes surge in May that catches anglers and hikers off guard. Cool maritime nights in coastal York and Hancock counties keep activity down in the daytime; dusk and dawn drive the worst of it.
Monthly Biting Intensity (Northeast)
Maine Mosquito Risk Profile
- WNV burden level
- Minimal
- about 5 confirmed cases annually
- EEE risk
- Rare but documented
- Peak biting season
- June through September
- Top urban risk areas
- Portland (Cumberland)
- Bangor (Penobscot)
- Lewiston (Androscoggin)
Signature habitat: coastal salt marsh, inland forested swamps.
Climate driver: Cool maritime climate compresses biting season; warming trend extending it.
Check Your Local Mosquito Risk
Ready to see current mosquito activity in your area? Get today's forecast and personalized risk assessment for your ZIP code.
Common Mosquitoes in Maine
Understanding which mosquitoes are active in Maine 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 Maine
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 Maine?
Live water temperatures and swim conditions for Sebago Lake, Moosehead Lake.
See Maine lake temperaturesWhen does mosquito season end in Maine?
Mosquito activity winds down after the first hard freeze, which in Maine typically arrives around Sep 28. See the local first-frost window and city-by-city freeze dates.
Maine first frost datesAlso worried about ticks in Maine?
Lyme disease risk and tick activity track different seasonal patterns than mosquitoes. See your Maine tick forecast.
View Maine tick forecastStay Safe in Maine
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