2021 Annual Mosquito Report

The City contracts with Clarke Mosquito for Mosquito Management Services. They have provided their 2021 Annual Report.

As the world began a slow return to post-COVID-19 conditions, 2021 also saw a return of more typical mosquito control activities. Last year, only four counties reported West Nile Activity, but that number increased more than ten-fold in 2021. In addition, rains in June produced nuisance mosquito brood hatchings that resulted in the highest July mosquito activity in three years.

“Warm and generally dry” was the go-to phrase for 2021 weather in the Chicago region. With the exception of June, which ranked as the 13th wettest, most of spring and summer were at or below average precipitation, skewing drier for most months in 2021.

But with that drier climate came excessive warmth. Chicago experienced its 4th warmest June, 5th warmest September and 6th warmest August in 2021. This early warmup and extended summer weather created conditions conducive to mosquito breeding.