Today's Mosquito Risk in Michigan: 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
- Lower Peninsula has the densest Aedes vexans floodwater hatches in the Great Lakes region; EEE risk concentrated in southwest swamps.
- Per mosquito-risk-model regional tier
- Highest-Risk Areas
- Wayne, Kent, Macomb, Ingham (WNV); Kalamazoo, Barry, Berrien (EEE)
Current Situation in Michigan
Michigan carries a moderate WNV burden of roughly 30 to 60 confirmed human cases annually, but the state also documented major Eastern Equine Encephalitis outbreaks in 2019 and 2020 with cases concentrated in Kalamazoo, Barry, and Berrien counties of the southwest Lower Peninsula. Cx. pipiens drives WNV transmission in the Detroit, Grand Rapids, and Lansing metros, while Aedes vexans floodwater hatches off Lower Peninsula wetlands produce some of the densest summer biting in the Great Lakes region. Aedes albopictus is expanding in the Detroit metro but stays limited statewide. The Upper Peninsula stays cool and forested, with boreal Aedes species like Aedes provocans and Aedes communis producing legendary spring biting around Pictured Rocks and Isle Royale despite minimal disease pressure. Biting season runs June through September.
Snapshot of the current mosquito situation in Michigan, drawn from CDC ArboNET surveillance and the regional risk model.
- Risk Level
- Moderate
- Peak Activity
- June through September
- Dominant Vector
- Northern House Mosquito (Culex pipiens)
Where Mosquitoes Breed in Michigan
Michigan mosquito habitat splits hard between the Lower Peninsula and the Upper Peninsula. The Lower Peninsula holds the floodwater swamp belt across Kalamazoo, Barry, Berrien, and Allegan counties that drove the 2019 and 2020 EEE outbreaks, with Allegan State Game Area as a focal habitat for Culiseta melanura bridge cycling. Saginaw Bay marshes and the Detroit River corridor sustain dense Cx. pipiens and Aedes vexans populations. The Lake Michigan and Lake Huron shoreline marshes produce coastal Aedes vexans hatches. The Upper Peninsula holds boreal wetlands across Hiawatha and Ottawa National Forests, with Pictured Rocks and Isle Royale producing massive spring Aedes communis and Aedes provocans hatches off snowmelt. Storm drains and tire piles across Detroit, Grand Rapids, Warren, Sterling Heights, and Lansing carry the urban Cx. pipiens load.
Hotspot Counties & Areas
- Wayne County (Detroit metro, Detroit River)
- Kent County (Grand Rapids)
- Macomb County (Warren, Sterling Heights)
- Ingham County (Lansing)
- Kalamazoo, Barry, and Berrien counties (2019 to 2020 EEE focus area)
- Allegan State Game Area
- Saginaw Bay marshes
- Pictured Rocks and Isle Royale (Upper Peninsula boreal Aedes)
Seasonal Activity Pattern
Biting starts in early June, peaks late July through August, and tapers through September. WNV cases concentrate in August across the Detroit, Grand Rapids, and Lansing metros. EEE risk in the southwest Lower Peninsula swamp counties peaks late August through September, the same window that produced the 2019 and 2020 outbreaks. Aedes vexans floodwater hatches across the Lower Peninsula peak in late June and July after spring rains. Upper Peninsula boreal Aedes biting peaks in mid to late June off snowmelt and runs into July, with Pictured Rocks and Isle Royale staying buggy well after the Lower Peninsula tapers. Heavy summer storms produce floodwater Aedes pulses along the Saginaw and Grand River bottomlands.
Monthly Biting Intensity (Midwest)
Michigan Mosquito Risk Profile
- WNV burden level
- Moderate
- about 30 to 60 confirmed cases annually
- EEE risk
- Documented; major outbreaks in 2019 and 2020
- Peak biting season
- June through September
- Top urban risk areas
- Detroit (Wayne)
- Grand Rapids (Kent)
- Warren (Macomb)
- Lansing (Ingham)
Signature habitat: Lower Peninsula floodwater swamps, Saginaw Bay marshes, Upper Peninsula boreal wetlands.
Climate driver: Lower Peninsula has the densest Aedes vexans floodwater hatches in the Great Lakes region; EEE risk concentrated in southwest swamps.
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Common Mosquitoes in Michigan
Understanding which mosquitoes are active in Michigan 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.
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 Michigan
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 Michigan?
Live water temperatures and swim conditions for Higgins Lake, Mullett Lake, Lake Michigan, and 1 more.
See Michigan lake temperaturesWhen does mosquito season end in Michigan?
Mosquito activity winds down after the first hard freeze, which in Michigan typically arrives around Oct 5. See the local first-frost window and city-by-city freeze dates.
Michigan first frost datesAlso worried about ticks in Michigan?
Lyme disease risk and tick activity track different seasonal patterns than mosquitoes. See your Michigan tick forecast.
View Michigan tick forecastStay Safe in Michigan
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