Forget the swampy stereotypes. The most mosquito-plagued city in the United States right now is not in Florida or Texas but on the Pacific coast, where warm evenings, dense neighborhoods, and year-round outdoor living have created ideal conditions for biting insects. Pest control data and travel reporting converge on the same conclusion: Los Angeles has become the country’s undisputed mosquito capital, and the ripple effects stretch well beyond Southern California.
I see that shift as more than a quirky ranking. It is a sign of how urban growth, climate patterns, and changing mosquito species are reshaping where Americans are most likely to be swatting at their ankles, from Los Angeles to Chicago and New York City, and even into Midwestern hubs like Detroit and Atlanta’s sprawling metro.
How Los Angeles climbed to the top of the mosquito charts
Los Angeles has long sold itself as a place of endless summer, and that near-permanent warm season is now showing up in pest control statistics. The city’s combination of mild winters, irrigated yards, and dense housing has pushed it to the top of multiple national rankings that track where mosquito control companies are busiest. One major national provider based in MEMPHIS, Tenn reported that Los Angeles, Calif took the number one spot on its annual Top list of mosquito hot spots, a ranking built from service calls that reflect real-world complaints rather than lab models, and that same report highlighted how the company, Terminix, now operates as part of Rentokil Terminix to monitor mosquito problems from coast to coast.
Another major player, Orkin, has reinforced that picture with its own nationwide ranking, which is based on the number of new residential mosquito treatments performed between early spring and the following March. In that list, Los Angeles ranked first, ahead of traditional mosquito magnets in the Southeast, and the company framed the surge as a direct response to how outdoor summer activities kick up demand for protection. When I look at those overlapping data sets, it is hard to escape the conclusion that the country’s mosquito epicenter has shifted firmly to the West Coast, even as many people still associate the worst bites with bayous and Gulf Coast marshes.
The surprising geography of America’s mosquito problem
What stands out in the latest rankings is not only that Los Angeles leads the pack but that some of the worst mosquito pressure is now concentrated in big, northern metros. According to one widely cited Top Mosquito Cities List, Los Angeles holds the top spot while Chicago and New York follow close behind, a pattern that undercuts the idea that only humid subtropical climates are at risk. That same list, described as a Top 50 M roster of mosquito trouble spots, shows how sprawling urban regions with dense housing and abundant standing water can rival any swamp when it comes to breeding grounds.
Travel coverage has picked up on the same trend. One detailed rundown of the most mosquito-infested destinations in the country named Los Angeles as the worst city for bites and noted that, in addition to L.A., some of the most affected places included Chicago and New York City, with a full list of the top 50 locations stretching from coastal hubs to inland metros. When I read that Jan feature, what struck me was how little the list resembled the old mental map of mosquito country. Instead of a cluster of Southern towns, it was a roll call of major economic centers where millions of people live, commute, and spend their summers outdoors.
Chicago, New York City, and the rise of northern mosquito hubs
Chicago has emerged as the clearest example of how a northern city can become a mosquito powerhouse. One local report noted that Chicago was named runner up as America’s most mosquito-ridden city, Only ranking behind Los Angeles, and emphasized that it led the way among Midwestern metros, with Detroit and Cleveland also appearing high on the list. Another national summary of mosquito season trends singled out Chicago as one of the cities seeing the biggest swarms, underscoring how lakefront humidity, summer storms, and dense neighborhoods can combine to create ideal breeding conditions even far from the Gulf Coast.
New York City is not far behind. In the same national rankings that put Los Angeles first and Chicago second, New York consistently appears in the upper tier of mosquito trouble spots, reflecting the sheer scale of its population and the patchwork of parks, rooftop gardens, and aging infrastructure that can trap water. A travel-focused breakdown of mosquito risk highlighted Chicago and New York City alongside Los Angeles as some of the most affected urban areas, and it pointed readers to a broader list of 50 cities where You can expect elevated mosquito activity. When I compare those findings with basic geographic snapshots of Chicago and New York, the common thread is clear: large bodies of water, dense housing, and summers that are warm enough, for long enough, to sustain multiple mosquito generations.
Beyond the coasts: Atlanta, Detroit, and the broader Top 50 M map
The mosquito story is not just coastal. In the Southeast, Atlanta remains a major hotspot, with its humid summers and tree-lined neighborhoods providing textbook conditions for mosquito breeding. A national release on mosquito season trends, datelined ATLANTA, framed the start of Mosquito season as a moment when some U.S. cities are seeing the biggest swarms, and it placed Los Angeles at the top of that list while also tracking how other metros are moving up or down the rankings. When I look at basic geographic data on Atlanta, the pattern is familiar: long warm seasons, frequent rain, and a mix of urban and suburban landscapes that can hide countless small pools of standing water.
The Midwest is increasingly prominent as well. Detroit, for example, appears in the same Midwestern cluster as Chicago and Cleveland in national mosquito rankings, reflecting how Great Lakes humidity and aging infrastructure can create pockets of stagnant water. A closer look at Detroit shows a city ringed by waterways and dotted with vacant lots, both of which can become breeding sites if not managed carefully. Industry-focused coverage of Orkin releases has described how the company’s Top 50 Mosquito Cities List for 2025, sometimes shortened in internal references to a 50 M roster, now includes a wide swath of Midwestern and Northern cities, from Chicago and Detroit to Minneapolis, Minn, underscoring that mosquito risk is no longer confined to the Sun Belt.
What the rankings say about risk, comfort, and how cities respond
Behind the rankings is a simple reality: more mosquitoes mean more discomfort and, potentially, more disease risk, even if most bites are merely annoying. The companies compiling these lists are not academic observers, they are responding to calls from residents who want to reclaim their yards, parks, and patios. One consumer-facing summary of Orkin data explained that the company reveals the country’s top spots for mosquitoes each year, using service records to rank cities by the number of treatments performed, and it noted that Orkin recently published its annual report to help residents understand where they stand. Another overview of mosquito season warned that as outdoor summer activities ramp up, so does the need for proactive mosquito control to help protect health and comfort, a reminder that these rankings are as much about quality of life as they are about entomology.
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