What’s the respiratory-virus “weather” where you are? Updated weekly.
Apr. 21, 2026: Special note! The CDC updated its website last week and now has a single page with info about wastewater data for Flu A, COVID, and RSV. They’ve also updated their all-blue maps to ones with multiple colors – much easier to viscerally understand. The data for the different diseases hides behind three tabs that are easy to miss, so I’m linking to each tab individually below.
Flu levels are down to low levels nearly nationwide, and COVID levels remain “low and stable,” per Outbreak Outlook. RSV levels continue to decline. For more information on respiratory disease activity in your area, see Force of Infection’s Outbreak Outlook (paywalled for the non-flu season).
National Wastewater Data
for Respiratory Viruses
US Centers for Disease Control
These pages show CDC data on flu A, COVID-19, and RSV in wastewater with a five- to 12-day delay. For example, when the maps are updated on April 14, they show the data for the week ending April 9. Once you get to the page, you’ll need to scroll down to see the map showing the wastewater levels in each state and the chart showing trends over time.
When a surge happens, virus levels in wastewater go up first – before case counts or hospitalizations.
Influenza A
Chart shows national and regional flu A levels over the past 12 months.
COVID
Chart shows national and regional COVID levels over the past 12 months.
RSV
Chart shows national and regional RSV levels over the past 12 months.
Weekly Influenza Surveillance Report
US Centers for Disease Control
The map on this page is based on how many people see their health care providers because they have a fever plus a cough and/or a sore throat. That group of symptoms is called “influenza-like illness,” or ILI.
The colors on the map tell you how much influenza-like illness has been reported in each state with a one- to two-week delay. For example, when the map is updated on April 14, it shows the data for April 1 – 7.
The levels shown on the map are based on symptoms only, not on test results.
COVID-19, Influenza, and RSV Wastewater Monitoring in the U.S.
Biobot Analytics
Biobot Analytics is a company that tests wastewater from sewers across the country.
This page shows line graphs that track levels of COVID, flu, and RSV in wastewater over time. Each graph shows results for the four regions of the US: The South, the Northeast, the Upper Midwest, and the West.
Wastewater Testing Dashboard
Verily
Verily is a company that tests wastewater from sewers across the country.
On this page, they show line graphs that track the levels of different viruses in wastewater over time. Use the dropdown menu to select the virus you want to see. The four lines in each graph represent regions of the US.
The WastewaterSCAN Dashboard
WastewaterSCAN
On this page, you can look at wastewater data for lots of different viruses, including COVID-19, flu, respiratory syncytial virus (RSV), and more.
Respiratory Illness Index
Walgreens
The Walgreens Respiratory Illness Index covers COVID-19 (top) and influenza (flu, bottom).
State and Local COVID-19 Wastewater Dashboards
The COVID-19 Data Dispatch
Roughly half of US states have their own dashboards that track COVID wastewater data. A few local and regional public health offices do, too.
Once you get to the site, scroll down a bit to find the list of links.
COVID-Safe Schools 