COVID-19: Mapped Cases by County

About our data

All data are laboratory-confirmed cases of COVID-19 that we extract from our live Wisconsin Electronic Disease Surveillance System (WEDSS) and freeze once a day. These numbers are the official state numbers, though counties may report their own totals independent of DHS. Combining the DHS and local totals may result in inaccurate totals.

Deaths must be reported by health care providers, medical examiners/coroners, and recorded by local health departments in order to be counted.

The number of people with negative test results includes only Wisconsin residents who had negative test results reported electronically to DHS or entered manually into the WEDSS electronic laboratory module. As a result, this number underestimates the total number of Wisconsin residents with negative test results.

Data shown below are subject to change. We strive for transparency and accuracy in our data, and as individual cases are investigated by public health, there may be corrections to the status and details of cases that result in changes to this information. Some examples of corrections or updates that may lead to changes to our data, such as case and negative counts and deaths going up or down, include: 

  • Update or correction of case's address, resulting in a change to their location of residence to another county or state,
  • Correction to laboratory result,
  • Correction to a case's status from confirmed to unconfirmed (for example, if they were marked as confirmed because a blood test detecting antibodies was positive instead of a test detecting the virus causing COVID-19),
  • De-duplication or merging and consolidation of case records,
  • Update of case's demographic information from missing or unknown to complete information.

For information on testing, see: COVID-19, testing criteria section.

Wisconsin and surrounding states and Great Lakes map image

View COVID-19 Maps

Download the following data:

Need more information? Look at our Data Dictionary (PDF) or visit our Data 101 section where you can find information on how we calculate and report COVID-19 data.



Number of cases by county and census tract data

Rate (cases per 100,000 people) of cases by county

Last Revised: September 11, 2020