Fogging Trucks Roll Tonight Across Unincorporated Denton County After Two WNV Traps Test Positive

If you live in unincorporated Denton County and you're planning to leave windows open tonight, this is your heads-up.

Denton County Public Health has reported two positive West Nile Virus mosquito traps in unincorporated areas of the county, and the response is starting immediately. Affected locations will be fogged three times beginning tonight, July 16, through Wednesday, July 22, weather permitting — with truck-based ultra-low volume fogging running between 9 PM and 5 AM each night.

This is a direct response to confirmed detections, not a precautionary measure. The county runs surveillance traps countywide all season; when traps come back positive, fogging follows. County public health has said that only one trap needs to be positive for fogging to occur in the surrounding area, so two positives in the same cycle moves things quickly.

The season is already active. Denton County Public Health reported the first human West Nile virus case of 2026 on July 10 — a Denton resident diagnosed with the non-neuroinvasive form of the disease. That case, combined with rising trap counts, puts the county well into its response posture for mid-July.

What to do before 9 PM tonight

The specific fog-zone maps are posted at DentonCounty.gov/WNV, along with mosquito maps, the latest news, and facts about WNV. Check it now. If your neighborhood is listed, the practical steps are straightforward: close your windows, bring pets inside, and hold off on patio time until after sunrise. Residents in affected areas are also being notified via emergency alerts and signage.

The fogging method is ultra-low volume pesticide application, which disperses a mist of microscopic airborne particles — typically less than 3 ounces of active ingredient per acre — designed to eliminate adult mosquitoes in flight. The spray targets the adult mosquito population. The virus moves from infected birds to mosquitoes to people; reducing the number of biting mosquitoes is how you interrupt that chain.

If you have asthma, another respiratory condition, or a compromised immune system, call the Denton County Health Department's West Nile hotline at 940-349-2907 before the trucks roll.

Between now and the end of spray season

Forest and evening walks are fine once the fog clears, but the county's standard guidance holds all summer. Drain standing water in your yard and neighborhood to minimize breeding sites: bird baths, flowerpots, clogged rain gutters. Dress in long sleeves and pants at dawn and dusk, and use EPA-registered repellent.