Phoenix is in the thick of mosquito season and it may soon get worse

Metro Phoenix is in the thick of mosquito season, and it's likely to get worse later this summer, the Maricopa County Environmental Services Department tells us.

Why it matters: Mosquitoes are more than just a nuisance — they can carry and transmit diseases like West Nile and dengue.

• Mosquito-borne illnesses cause more than 700,000 deaths globally each year, according to the World Health Organization .

State of play: Through June 20, Maricopa County has reported one locally acquired case of West Nile virus and nine cases of dengue acquired by residents who had recently traveled.

• No deaths have been recorded.

The big picture: Mosquito season in the Valley used to run May through October, but it's starting earlier and lasting longer, county environmental services spokesperson Johnny Diloné told Axios.

• Many American cities, including ours, have seen an increase in the number of days that are hospitable to mosquitoes over the past several decades — likely because of climate change, nonprofit climate science research organization Climate Central said in a 2023 report.

Zoom in: Diloné said the county does year-round mosquito surveillance and abatement to keep the potentially dangerous pests at bay.

• Workers set more than 800 traps across metro Phoenix each week. If they catch any mosquitoes, they take them to the county lab for analysis.
• The county sprays a one-square-mile area around the trap if a mosquito is found to be carrying a disease, if there are more than 30 female mosquitoes (the only ones that suck our blood) or 200 total mosquitoes.

Stunning stat: Mosquitoes require stagnant water to breed, but they need as little as fits in a water bottle cap, Diloné said.

• He encouraged residents to check plant pots, bird baths, kiddie pools and other shallow dishes for pooled water.

Friction point: Matt Taft of local Bug Eyes Pest Control told Axios that part of the problem with controlling mosquitoes in the Valley is the proximity of our homes. Even if you keep your yard free of standing water, a neighbor may not, putting your yard at risk.

Be smart: Maricopa County recommends using an EPA-registered insect repellent when outdoors, especially from dusk to dawn.

What we're watching: Mosquito season will likely peak when monsoon season hits later this summer and rainwater pools in yards, Diloné said.