Unusually High West Nile Virus Surge in Minnesota After Huge Spike in Mosquito Activity

Mosquitoes in Minnesota have been absolutely relentless this summer. Here in the Land of 10 Billion Mosquitoes, it feels like you can’t walk from your car to your front door without being eaten alive. These tiny bloodsuckers are out in full force, and they are thriving thanks to our warm, wet summer and endless standing water.

Last week, the mosquito population spiked well above average to the highest amount we've seen since 2020, and just when you thought it couldn’t get worse, they’re now reportedly testing positive for West Nile virus all across the Twin Cities metro.

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Did you know Minnesota is actually home to more than 50 species of mosquitoes, but only a handful are responsible for biting humans? The state’s mosquito season typically runs from May through September, peaking in mid to late summer. Mosquitoes breed in standing water, which means all those lakes, ponds, puddles, and even clogged gutters make for prime real estate.

The Culex tarsalis mosquito is the main culprit behind West Nile transmission, and it thrives in open, rural areas and is most active at dawn and dusk.

And fun fact (or maybe not so fun): only female mosquitoes bite because they need the protein in blood to lay eggs.

West Nile Virus Detected in All 7 Twin Cities Metro Counties

The Metropolitan Mosquito Control District (MMCD) says mosquitoes carrying West Nile virus have been detected in all seven counties of the Twin Cities metro area. What’s especially concerning is that the Culex tarsalis mosquito responsible for spreading the virus to humans is showing up in record-high numbers for July.

Experts say these are numbers we typically see in late August, not mid-summer. The MMCD says that out of 187 mosquito pools tested last week, 34 came back positive for West Nile virus.

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West Nile in Minnesota: A Growing Summer Concern

West Nile virus was first found in Minnesota in 2002 and has since become the state’s most commonly reported mosquito-borne disease.

The Minnesota Health Department says farmland and prairies, especially in western and central Minnesota, are hot spots for Mosquitoes that transmit West Nile.

According to CDC data, in 2024, 35 people were infected with the West Nile virus in Minnesota, with most cases occurring in August and September.

The first human case of West Nile virus in Minnesota in 2025 has been found in Dakota County, the MMCD says.

What You Should Know About West Nile Virus in Minnesota

The Minnesota Department of Health says it’s not uncommon to find West Nile-positive mosquitoes during the summer, but this early spike in activity raises concern. That’s because the virus can be dangerous, especially for people over 60 or those with weakened immune systems.

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Most people who get West Nile don’t feel very sick, and many won’t even know they have it. But for some, it can lead to serious complications like encephalitis or meningitis. Symptoms can include:

• High fever
• Severe headaches
• Rash
• Vomiting
• Joint pain
• Swollen lymph nodes

Tips to Protect Yourself From Mosquito Bites

To lower your risk of infection, health officials recommend a few simple but effective precautions. Start by using an insect repellent that contains DEET or other EPA-approved ingredients.

When you’re outdoors, especially during peak mosquito hours around dawn and dusk, wear long sleeves and pants to reduce skin exposure. It’s also a good idea to limit time outside during those high-activity periods if you can.

And around your home, be sure to remove any standing water. Things like birdbaths, buckets, and clogged gutters since those spots are mosquito breeding hotspots.