Today's Mosquito Risk in Missouri: 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 20 to 60 confirmed cases annually
- Based on CDC ArboNET surveillance data
- Risk Tier
- Tier 3: Moderate
- Bootheel sits at the northern edge of the Gulf coastal mosquito regime; Ozarks stay moderate.
- Per mosquito-risk-model regional tier
- Highest-Risk Areas
- Jackson, St. Louis (WNV); Pemiscot and Dunklin (Bootheel Aedes aegypti and flood mosquitoes)
Current Situation in Missouri
Missouri carries a moderate WNV burden of roughly 20 to 60 confirmed human cases annually, distributed across the Kansas City and St. Louis metros, the Mississippi River Bootheel in the southeast, and the Ozark hollows. The Bootheel sits at the northern edge of the Gulf coastal mosquito regime and pulls Aedes vexans, Psorophora, and Cx. quinquefasciatus pressure off the lower Mississippi floodplain. Cx. pipiens dominates Culex transmission in the northern half of the state, with Cx. quinquefasciatus taking over south of I-70. Aedes albopictus is established across the southern half. Aedes aegypti shows sporadically in the Bootheel. EEE is rare. The Ozark Plateau hollows and Mark Twain National Forest produce woodland Aedes triseriatus and Aedes vexans off forested wetlands. Biting season runs May through October.
Snapshot of the current mosquito situation in Missouri, 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) north; Southern House Mosquito (Culex quinquefasciatus) south
Where Mosquitoes Breed in Missouri
Missouri mosquito habitat is the most varied in the Midwest. The Mississippi River Bootheel in the southeast holds the highest pressure in the state, with the Big Muddy River bottoms and Mingo National Wildlife Refuge producing dense Aedes vexans, Psorophora, and Cx. quinquefasciatus populations. The Missouri River floodplain from Kansas City through Jefferson City and St. Charles sustains steady Cx. pipiens and Aedes vexans populations. The Ozark Plateau hollows and Mark Twain National Forest produce woodland Aedes triseriatus off treeholes and Aedes vexans off beaver ponds. The Ozark National Scenic Riverways and the Lake of the Ozarks shoreline hold dense seasonal Aedes hatches. Storm drains and tire piles across Kansas City, St. Louis, Springfield, and Independence carry the urban Aedes albopictus and Cx. pipiens load.
Hotspot Counties & Areas
- Jackson County (Kansas City metro)
- St. Louis City and St. Louis County (St. Louis metro, Mississippi River)
- Greene County (Springfield, Ozark Plateau edge)
- Bootheel counties (Pemiscot, Dunklin, Mississippi River floodplain)
- Mingo National Wildlife Refuge
- Mark Twain National Forest hollows
- Lake of the Ozarks shoreline
- Ozark National Scenic Riverways
Seasonal Activity Pattern
Biting starts in early May in the Bootheel, mid May in the metros, peaks late July through August, and tapers through October. WNV cases concentrate in August across the Kansas City and St. Louis metros and the Bootheel counties. The Bootheel runs warmer and longer than the rest of the state, with biting tailing into November in mild fall years. Aedes albopictus daytime biting in suburban yards across the southern half of the state runs heavy from June through September. Heavy summer storms produce floodwater Aedes pulses along the Missouri and Mississippi bottomlands. Ozark hollows and Mark Twain National Forest run a week or two behind the metros on phenology, with peak forest biting in mid to late July.
Monthly Biting Intensity (Midwest)
Missouri Mosquito Risk Profile
- WNV burden level
- Moderate
- about 20 to 60 confirmed cases annually
- EEE risk
- Rare
- Peak biting season
- May through October
- Top urban risk areas
- Kansas City (Jackson)
- St. Louis (St. Louis City)
- Springfield (Greene)
- Columbia (Boone)
Signature habitat: Mississippi River Bootheel, Missouri River floodplain, Ozark hollows, Mark Twain National Forest swamps.
Climate driver: Bootheel sits at the northern edge of the Gulf coastal mosquito regime; Ozarks stay moderate.
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Common Mosquitoes in Missouri
Understanding which mosquitoes are active in Missouri 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 Missouri
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 Missouri?
Live water temperatures and swim conditions for Lake of the Ozarks.
See Missouri lake temperaturesWhen does mosquito season end in Missouri?
Mosquito activity winds down after the first hard freeze, which in Missouri typically arrives around Oct 22. See the local first-frost window and city-by-city freeze dates.
Missouri first frost datesAlso worried about ticks in Missouri?
Lyme disease risk and tick activity track different seasonal patterns than mosquitoes. See your Missouri tick forecast.
View Missouri tick forecastStay Safe in Missouri
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