Chicago Ranks 2nd Worst for Mosquitoes in 2026 Amid Climate Concerns
Chicago has been ranked the second-worst city in the United States for mosquito activity, according to a report by Orkin Pest Control Service. The ranking, based on residential mosquito treatments performed between March 2025 and March 2026, places Chicago just behind Los Angeles and ahead of New York. Experts suggest that climate change is playing a significant role in expanding the range of mosquito species, including those carrying diseases like West Nile virus and yellow fever. Local mosquito control programs, such as those by the Chicago Department of Public Health, are actively treating storm drains with larvicide and conducting mosquito trapping and testing. While Cook County has not seen a significant increase in mosquito populations overall, invasive species and higher rates of West Nile virus in native species have been observed. The mosquito season is also lengthening due to shorter winters, increasing the potential for disease transmission.