Flu is Low in Ann Arbor and Grand Rapids, and Moderate in Detroit and Detroit.
Influenza risk levels are based on CDC ILINet surveillance data, laboratory-confirmed flu tests, and hospitalization rates. Prevalence reflects estimated active flu cases per 100,000 population. Risk scores incorporate strain circulation patterns and vaccination coverage rates.
Data is updated weekly during flu season (October–May) and monthly during off-season.
Sources: CDC FluView, ILINet, state health departments, Hubbub World epidemiological model
Last updated: April 20, 2026
Data refreshed weekly