List of open weather radar data repositories

German Weather Service (DWD)

https://opendata.dwd.de

National Oceanic and Atmospheric Administration (NOAA)

https://www.ncdc.noaa.gov/data-access/radar-data

Royal Netherlands Meteorological Institute (KNMI)

https://data.knmi.nl/datasets?q=radar

wradlib example data

https://github.com/wradlib/wradlib-data