Mosquito Season Is Here—These 10 Cities Will Have It the Worst

Summer brings days filled with sunny skies, outdoor activities, and backyard entertaining, as well as some uninvited guests that can put a damper on the fun—mosquitos. But, according to Orkin’s 2025 Top 50 Mosquito Cities List, some areas of the U.S. will experience more of these pesky insects than others this summer. The annual list is based on the number of new residential mosquito treatments performed by Orkin from April 2024 through March 2025. Ahead, we're sharing a closer look at which cities will be most affected by mosquitoes this season. 

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Top 10 Mosquito-Ridden Cities

According to the report, Los Angeles is the top spot for the fourth year in a row. Chicago, New York, Atlanta, and Detroit round out the top five, with Detroit making its debut in the top rankings. Cleveland and Denver also broke into the top 10 for the first time.

As for statewide, California is home to the most mosquito activity, with five cities in the top 50, including Los Angeles, San Francisco, Sacramento, San Diego, and Fresno. Orkin attributes the high mosquito populations to the state's high temperatures and proximity to standing water.

Here's a complete look at the top 10 cities predicted to have the most mosquito activity this summer:

1. Los Angeles
2. Chicago
3. New York
4. Atlanta
5. Detroit
6. Houston
7. Dallas
8. Washington, D.C.
9. Cleveland
10. Denver
    

Importance of Mosquito Control

Besides being annoying, mosquitoes are also considered a health risk since they can transmit diseases such as West Nile and Zika viruses and malaria, which is deadly if not diagnosed and treated quickly. According to the U.S. Centers for Disease Control and Prevention (CDC), there are about 2,000 reported cases of malaria in the U.S. annually, with most cases occurring in people who contracted the disease while traveling to another country.

How to Prevent From Mosquitoes

Because you can’t tell which mosquitos spread viruses, protecting yourself from as many bites as possible is essential. "Mosquito control isn’t just about avoiding itchy bites,” said Orkin entomologist Frank Meek. “It’s about safeguarding your health and your community. Proactive measures are key to controlling these seasonal surges in mosquito activity.”

To help reduce the chance of mosquito bites and infestation, Orkin offers four preventive measures, which homeowners can remember with the acronym BITE:

• Block access to skin: Wear long sleeves and pants and apply CDC-recommended repellents with one of these active ingredients: DEET, Picaridin, IR3535, oil of lemon eucalyptus, para-menthane-diol, or 2-undecanone. Keep in mind that some of these ingredients should not be used on young children.
• Install tight-fitting screens: Place screens on windows and doors to prevent mosquitoes from entering your home.
• Trim shrubs, grass, and other vegetation: Don't let your plants and grass get too tall as mosquitoes gather in these areas.
• Eliminate standing water: Stagnant water is a breeding ground for mosquitoes. Properties near ponds, marshes, and depressions are at greater risk of attracting mosquitoes.

From now until June 30, for every mosquito control service purchased, Orkin will donate $25 to the American Red Cross, up to $250,000, as part of its Mosquitoes Don’t Deserve a Drop campaign. The donations will help maintain a healthy blood supply across the U.S. while encouraging homeowners to take proactive steps against mosquito-borne illnesses.