Flu levels in wastewater are rising across most states, with several experiencing very high activity.

Wastewater Viral Activity Levels for Influenza A by State for week ending Dec 27, 2025. Hover the cursor over a State to find more details.

The Wastewater Viral Activity Level is a calculated measure that aggregates wastewater sample data to get state, regional, and national levels and see trends over time. The value associated with the Wastewater Viral Activity Level is the number of standard deviations above the baseline, transformed to the linear scale.
Chart: Bob HawkinsSource: CDC National Wastewater Surveillance SystemGet the dataCreated with Datawrapper