Florida has mosquitoes in enormous numbers. Roughly 90 species live in the state, more than almost anywhere else in the continental U.S., and that number keeps growing as new species arrive from other parts of the world. The combination of warm temperatures, heavy rainfall, and abundant standing water makes Florida one of the most mosquito-dense states year-round.
Why Florida Has So Many Mosquitoes
Mosquitoes need warmth, moisture, and standing water to breed, and Florida delivers all three in excess. The state’s subtropical and tropical climate means temperatures rarely drop low enough to kill off mosquito populations the way a northern winter would. Summers bring daily afternoon thunderstorms that fill every ditch, puddle, birdbath, and storm drain with fresh breeding habitat. Florida also has more than 7,700 lakes, vast stretches of swamp and marshland, and a water table so high that low-lying areas stay damp for weeks after rain.
Most of the roughly 90 species documented in Florida are native, but the list is expanding. University of Florida mosquito biologists continue to identify new species that have been introduced from elsewhere in the world, likely through shipping ports and international travel. Two of the most common biters, the yellow fever mosquito and the Asian tiger mosquito, are themselves invasive species that thrived once they reached Florida’s hospitable environment.
When Mosquito Season Peaks
Mosquito season in Florida runs from March through October, with mosquitoes most active when temperatures sit in the upper 70s to 90s°F. That means peak biting season lines up almost perfectly with the state’s rainy season, which typically runs June through September. During those months, daily rain creates new breeding pools faster than they can evaporate.
Unlike northern states where mosquitoes vanish after a hard freeze, Florida’s mild winters let some species remain active year-round, especially in South Florida. Miami, Fort Lauderdale, and the Keys rarely see temperatures cold enough to eliminate adult mosquitoes entirely. Central Florida gets a reprieve in December and January, but it’s short. North Florida, around Jacksonville and Tallahassee, has the closest thing to a true off-season, though even there mosquitoes can appear on warm winter days.
Diseases Mosquitoes Carry in Florida
Florida’s mosquitoes aren’t just a nuisance. The state actively monitors for several mosquito-borne illnesses, including West Nile virus, Eastern equine encephalitis, St. Louis encephalitis, dengue, chikungunya, Zika, and malaria. Most of these are rare, but they do occur.
West Nile virus is the most consistently detected. In 2025, Florida confirmed positive samples from humans, horses, and surveillance animals across 25 counties. Eastern equine encephalitis, a far more dangerous but less common virus, was detected in horses and sentinel chickens across 22 counties in the same period. Both viruses circulate primarily between mosquitoes and birds, with humans and horses as incidental hosts.
Dengue is the disease that has drawn the most attention in recent years. In 2025, Florida reported 40 locally acquired dengue cases, meaning those people were bitten by an infected mosquito within the state rather than catching the virus abroad. The yellow fever mosquito, which thrives in urban areas and bites during the day, is the primary carrier. Dengue outbreaks tend to be localized and tied to specific neighborhoods where that species is abundant. Meanwhile, 220 additional dengue cases were linked to international travel, a reminder that Florida’s heavy tourist and travel traffic constantly reintroduces tropical diseases.
Zika and chikungunya, both significant concerns a few years ago, had zero locally acquired cases in Florida in 2025. Malaria had 38 travel-associated cases but no local transmission.
How Florida Controls Mosquitoes
Florida invests more in organized mosquito control than virtually any other state. Many counties operate dedicated mosquito control districts with their own budgets, staff, and aircraft. The approach typically combines several methods rather than relying on any single one.
Larviciding targets mosquitoes before they become adults. Crews apply biological agents to standing water using backpack sprayers, trucks, or helicopters. These products kill larvae in ditches, ponds, and storm drains without significant harm to other wildlife. Adulticiding, the fogging that residents sometimes notice, uses truck-mounted sprayers that release a fine mist during early morning hours, typically between 2:00 and 6:30 a.m., when mosquitoes are active but most people and pollinators are not. Districts rotate the chemicals they use to prevent mosquito populations from developing resistance.
Surveillance is the other major component. Counties maintain networks of traps and sentinel chicken flocks (chickens that are tested regularly for mosquito-borne viruses) to detect disease activity before human cases appear. When virus activity spikes in an area, targeted spraying increases.
Protecting Yourself From Bites
Repellents containing DEET remain the most effective option. A product with about 24 percent DEET provides roughly five hours of protection, while a 10 percent concentration lasts about two hours. Higher concentration means longer protection, not stronger protection. The maximum recommended concentration for children over two months old is 30 percent; repellents should not be used on infants younger than two months.
Picaridin and oil of lemon eucalyptus are alternatives that provide protection comparable to about 10 percent DEET. Permethrin is effective but should only be applied to clothing, not skin. It needs to dry completely before you wear the treated garment. For outdoor time during peak hours (dawn and dusk for most species, daytime for the yellow fever mosquito), long sleeves and pants reduce exposed skin.
Reducing Mosquitoes Around Your Home
Female mosquitoes need only a bottle cap’s worth of standing water to lay eggs, so eliminating water sources around your property makes a real difference. The obvious targets are flowerpot saucers, old tires, clogged gutters, and pet water bowls. Less obvious are yard drains. They can appear dry on the surface while holding small pools of water in the drain tubes below, producing a steady supply of mosquitoes all season.
You can screen yard drains with a piece of window screen or foam insert to block mosquitoes from reaching the water inside. Check them after rain to make sure water isn’t backing up around the drain. If it is, remove the screen temporarily, let the water flow through, and replace it. Inspect screens monthly for tears. Any container that holds water and sits outdoors for more than a few days is a potential nursery, so dumping and scrubbing containers weekly breaks the breeding cycle. Mosquito larvae take about a week to develop into adults, so consistency matters more than perfection.