Change in annual days hospitable for mosquitoes, 1979 to 2022
In select cities; Days per year with temperatures between 50°–95° F and at least 42% relative humidity
Map of the U.S. showing the change in the annual days hospitable for mosquitoes from 1979 to 2022. Southern cities are generally reporting far fewer mosquito days per year, with San Antonio seeing a decline in 85 days from 1979 to 2022. Cities in the Rust Belt and Northeast, as well as Arizona and parts of the Pacific Northwest, have had the greatest increases in mosquito days per year. Flagstaff, Ariz. had 48 more mosquito days in 2022 compared to 1979.
