Denver makes the top 10 in this year’s list of the worst cities in America for mosquitoes
May 6, 2026, 5:09 PM
If you thought the Mile High City’s dry winter would spare us from mosquito season, you have some bad news waiting on the patio.
Denver ranked No. 10 on Orkin’s 2026 Mosquito Cities List, released Monday, placing it among the worst cities in the country for mosquito activity — ahead of traditional warm-weather pest magnets like Miami (No. 17), Orlando (No. 19) and Tampa (No. 16).
The annual ranking, based on the number of new residential mosquito treatments performed by Orkin between March 2025 and March 2026, reflects where pest control demand is highest — a proxy for where the insects are most aggressively bugging homeowners.
Los Angeles held the top spot for the sixth consecutive year, followed by Chicago and New York.
Denver’s placement underscores that shift. A city better known for snow forecasts and sun-baked hiking trails is now competing with Houston, Dallas and Atlanta on a list historically dominated by humid Southern and Gulf Coast metros.
The full top 10:
- Los Angeles
- Chicago
- New York
- Detroit
- Atlanta
- Washington, D.C.
- Houston
- Dallas
- Cleveland
- Denver
The ranking may surprise Front Range residents accustomed to thinking of mosquitoes as someone else’s problem, but Colorado’s mosquito landscape is more complex than its reputation suggests.
Denver’s extensive parks, irrigation systems, urban creek corridors — including the South Platte River and Cherry Creek — and the city’s network of stormwater detention ponds all create standing-water habitat where mosquitoes breed. The semi-arid climate is offset by regular summer afternoon thunderstorms that leave behind pooled water in gutters, flower pots, window wells (as one Falcon bear recently discovered) and neglected birdbaths.
The Orkin data does not measure mosquito population directly — it measures treatment demand. Denver’s rapid population growth over the past decade, which has added hundreds of thousands of residents to the metro area, likely contributes to higher service volume simply by putting more people in homes requesting pest control. The ranking should be understood in that context.
The full list of 50 cities is available at orkin.com.
