Why Los Angeles County Mosquito Activity Is Elevated in 2026

How Humidity and Warm Weather Help Mosquitoes Persist

Because of their tiny size, mosquitoes require areas where cool shade, moisture, and humidity allow them to reduce the drying effects of the Pasadena sun. This can encourage mosquitoes to seek refuge within residential areas where residents increase lawn and garden waterings or utilize sprinklers for a break from the heat. Meanwhile, rainfall and leaf litter can increase the amount of decaying vegetation that can hold small pools of water and provide areas of humidity for mosquito resting.

The strange weather patterns and temperatures within Los Angeles County are contributing to an increase in mosquito pressure in Pasadena, as well. The record-breaking humidity and temperatures create more areas where mosquitoes can thrive, which may have contributed to an increase in West Nile virus cases. In the September 22, 2026 report, the Los Angeles Times described this as one of the more severe West Nile virus seasons in recent memory.

What the 2026 West Nile Numbers Mean for Residents

As of September 22, 2026, Los Angeles County reported 100 West Nile virus cases and five deaths, an unexpected increase from the previous 22 cases and two deaths in 2025. While prolonged humidity can create conditions that support mosquito pressure across the county, it doesn’t automatically mean that every mosquito in Pasadena is carrying West Nile virus. 

This information is meant to inform Pasadena residents of the increased risks of West Nile virus exposure, in order to encourage residents to take precautions to reduce activity around their homes. Seek medical care if you develop symptoms of West Nile virus.

Reduce Standing Water and Mosquito Habitat at Home

While the news of West Nile virus may create cause for concern, there are steps you can take to reduce mosquito resting and breeding areas around your Pasadena home. For resting areas, it’s important to focus on areas where shade, humidity, and moisture encourage mosquito activity. 

Trim lawns and perimeter areas of the yard, reduce leaf litter or brush, and trim areas of dense vegetation. For breeding, reduce the amount of standing water that can be found around your Pasadena home. Dump water from planters, children’s playsets, bird baths, and other containers within 24-48 hours after rainfall. Ensure gutters and downspouts are clear of leaf litter in order to promote proper drainage, and take note of areas where low-lying ground or uneven pavement create puddles where mosquitoes can breed.

How Professional Mosquito Control Fits In

Professional mosquito control treatments in Pasadena can help to strengthen the everyday efforts residents take to reduce mosquito breeding and resting habitats. Our treatment plans at Mosquito Squad of Pasadena begin with a thorough property inspection in order to learn the layout, inspect mosquito activity, and note areas of concern. This allows us to create a tailored plan that suits your home and needs.

Our traditional mosquito control plan, Barrier Treatment Plus, is designed to reduce and control mosquitoes for up to 21 days at a time. This potent insecticide binds to the surface to create a barrier of defense that withstands regular rainfall, repels mosquitoes, and disrupts the cycle of breeding. Our trained technicians in Pasadena will apply your barrier treatments to targeted areas around your yard where mosquito harborage is likely to be found.

Get Mosquito Control Help From Mosquito Squad of Pasadena

If your home in Pasadena is experiencing the effects of mosquito pressure, our team is here to help. Through comprehensive mosquito control offerings and recurring treatment plans, we can help to reduce and control the mosquito population at your home for up to 21 days at a time.

Call (213) 238-5564 or request a free quote online to learn more.