I have to start with the caveat that I strongly dislike (hate is a strong word) ZIP Codes with a passion for mapping out any data, but desperate times and desperate measures (be on the lookout for an improved spatial process soon). Not all of eastern Washtenaw County is a hot-spot nor is all of northern Monroe County. Ypsilanti and Carleton are likely hostpots.

ZIP Code has become an default for municipal governments and in particular for health data. I assume because of the perceived “safety” of releasing case data that might be impossible to pinpoint within a ZIP Code rather than say a smaller geography like a Census Block Group. There still remains the possibility that there are only 10 houses in a ZIP Code and you could easily determine which of the 10 has a case of a particular disease.

At any rate, all the counties in the Southeast Michigan Council of Governments (SEMCOG) region are publishing a data dashboard that includes case counts at the ZIP Code level. However, not all of them present the data in the same way.

• Detroit only offers a map image by ZIP, no machine readable data tables.
• Wayne County locks down their data dashboard and reports at the “community” level, which thankfully in Wayne County (except for Dearborn) largely matches with ZIP Codes.
• Oakland County includes death counts. They normalize by cases per 10,000 people
• Macomb County has a detailed dataset of daily new cases, but reports limited data at the ZIP Code level beyond a case “count”
• Washtenaw County shares a “frequency” of cases by ZIP Code
• Monroe County shares case counts
• Livingston County shares a map, but the dataset API isn’t open to the public so was dropped when I made the map

ZIP Code data may be more geographically specific than County, but still needs more nuance and clarity.