Mosquito Season 2025: 3 Cities Facing Increased Mosquito Populations This Season

As the National Pest Management Association (NPMA) warns in its latest Public Health Pest Index, several U.S. cities are poised to experience a sharp increase in mosquito activity this spring. While a chilly, dry start to winter may have temporarily slowed breeding in some regions, warming temperatures and forecasted rainfall are setting the stage for a major mosquito resurgence across parts of the country.

Mosquitoes are more than just a backyard nuisance—they are vectors for dangerous diseases like West Nile virus, dengue, malaria, and Eastern equine encephalitis (EEE). With shifting weather patterns influencing pest behavior, early awareness and prevention are more critical than ever.

Culex mosquito on skin

Cities Bracing for a Mosquito Boom in 2025

While ticks, cockroaches, and rodents are also on NPMA’s radar, the following locations have been flagged for heightened mosquito activity this season:

1. Florida

A dry early winter gave residents a short reprieve from mosquitoes, but don’t be fooled—warmer weather and increased spring rainfall are forecasted to create ideal breeding conditions. From Miami to Tampa to Jacksonville, Florida residents should prepare for mosquito pressure to build quickly.

2. San Antonio, TX

Record-breaking warmth throughout winter has allowed mosquito populations to remain active. As spring unfolds, expect an early surge in bites and related health concerns across San Antonio and surrounding areas.

3. New Orleans, LA

Historic winter storms may have driven rodents and cockroaches indoors, but rising temperatures are expected to fuel a strong comeback for mosquitoes in the region. The city's humid, subtropical climate is an ideal incubator for mosquito breeding.

Mosquito-Borne Diseases in the U.S.

Although mosquitoes are often seen as little more than an itchy nuisance, they are among the deadliest creatures on the planet due to their ability to transmit life-threatening diseases. In the United States, four mosquito-borne illnesses present significant health threats: West Nile virus, dengue fever, EEE, and malaria.

West Nile Virus

West Nile Virus (WNV) is the most widespread mosquito-borne disease in the U.S., first detected during a 1999 outbreak in New York City that resulted in encephalitis cases and fatalities. Since then, it has been confirmed in all 48 continental states, including Florida, Texas, and Louisiana.

While 80% of infections are asymptomatic, up to 20% may experience flu-like symptoms including fever, headache, and muscle aches. In less than 1% of cases, the virus can cause severe neurological conditions such as encephalitis, meningitis, or paralysis, sometimes leading to death.

There is no specific treatment, making prevention—like avoiding dusk-to-dawn exposure, wearing protective clothing, and using mosquito repellent—critical.

Dengue Fever

Dengue Fever is a mosquito-borne viral illness prevalent in tropical regions such as Asia, Africa, and the Caribbean, and has increasingly emerged in the United States. Locally transmitted outbreaks have been reported in areas like Key West, Florida, and along the Texas-Mexico border, including cities such as San Antonio.

Symptoms usually appear 5 to 7 days after a mosquito bite and include high fever, severe headache, muscle and joint pain, and a rash—giving rise to its nickname, “break bone fever.” While most cases resolve within a week, some may progress to dengue hemorrhagic fever, a more severe and potentially fatal form. With no specific treatment or vaccine available, prevention is essential.

Eastern Equine Encephalitis

Eastern Equine Encephalitis (EEE) is a rare but potentially deadly disease spread through the bite of an infected mosquito. While only 5–10 human cases are typically reported annually in the U.S., outbreaks can be severe - as seen in 2019 when 28 cases and 10 deaths were recorded, the highest in a decade.

EEE can cause flu-like symptoms in mild cases, but in severe cases, it affects the brain, leading to convulsions, coma, or even death. With a fatality rate of about 30% and lasting neurological issues for many survivors, early detection and mosquito prevention are essential.

Malaria

Malaria, though eradicated as a public health concern in the U.S. in the 1950s, still presents a risk today. Approximately 1,500 cases are reported to the CDC each year, primarily among travelers returning from regions where malaria is endemic. Although locally transmitted cases remain rare, the mosquito species capable of carrying the malaria parasite still exist in the U.S., leaving open the possibility of reintroduction. There is no specific antiviral treatment for malaria, and individuals may experience a range of symptoms, some of which can be severe or even fatal.

How to Prevent Mosquitoes and Protect Your Health

Preventing mosquito bites is the most effective way to avoid the diseases they carry, and it starts with a few simple but essential steps:

Use insect repellent containing at least 20% DEET or another EPA-registered ingredient like picaridin, IR3535, or oil of lemon eucalyptus.

Wear long-sleeved shirts and long pants to minimize exposed skin.

Avoid going outdoors at dawn and dusk, when mosquitoes are most active.

Use a small fan at outdoor gatherings to help keep mosquitoes away.

Eliminate standing water at least once a week. Mosquitoes can breed in as little as half an inch of water.

Empty and clean items like birdbaths, flowerpots, kiddie pools, pool covers, and grill covers after rain.

Clear debris from gutters to prevent water buildup.

Remove unneeded vegetation or trash around standing water sources.

Introduce mosquito-eating fish like gambusia, green sunfish, bluegills, or minnows to permanent water features.

Ensure all windows and doors have tight-fitting screens; repair any holes or tears.

Contact a licensed mosquito control professional if you suspect a mosquito infestation.

Reach out to your local mosquito abatement district for guidance or treatment options in your area.

Here’s a quick guide to mosquito prevention you can use around your home:

Preventing mosquito breeding grounds around the house infographic

Contact a Mosquito Control Professional

When it comes to mosquitoes, store-bought sprays and DIY tricks can only go so far. These pests are persistent, and without the right strategy, they’ll keep coming back.

Working with a licensed mosquito control professional gives you access to expert knowledge, proven treatments, and customized plans that target both adult mosquitoes and their breeding grounds. For lasting relief and peace of mind, skip the guesswork and partner with a pro.