The City of Watertown is preparing for mosquito season with a targeted control program focused on reducing the risk of West Nile Virus. While the chance of serious illness is low, we treat every case as one too many. Our approach combines larvicide treatment, adult mosquito spraying, and public education.
When and Where We Spray
Spraying occurs only when necessary. Our team monitors mosquito trap counts and weather conditions to decide when to activate spraying. Applications typically happen at dusk or early morning, when mosquitoes are most active. Notices will be shared in advance through local radio, the City’s homepage, and social media.
Staying Safe During Spraying
While the health risk from mosquito spray is minimal, some people—especially those with chemical sensitivities or underlying health conditions—may prefer to take extra precautions. It’s best to stay indoors during spraying and for about an hour afterward. Close windows and doors, bring pets and outdoor items inside, and avoid direct contact with the spray. If needed, rinse skin or outdoor surfaces with soap and water after exposure.
What You Can Do at Home
Mosquitoes need standing water to breed. A few minutes of property maintenance each week can make a big difference. Dump water from flowerpots, bird baths, buckets, and anything else that collects rain. Keep gutters clear, repair leaky hoses, and store boats or tires so they stay dry. Even ornamental ponds can become breeding grounds—consider adding mosquito-eating fish if water can’t be drained.|
Reduce the chance of being bitten by wearing long sleeves and pants at dawn or dusk, using insect repellent with DEET or other EPA-approved ingredients, and keeping your yard tidy. Check that window and door screens are in good condition, and swap white bulbs for yellow bug lights, which attract fewer insects.
Need More Information?
For spraying questions, contact the Park, Rec & Forestry Department at (605) 882-6260. Visit to learn more: www.cdc.gov/westnile