Voter turnout percentages for Nov 3, 2020 election
Chicago, IL (city only, not Cook Co): 61.4%
St Louis, MO: 65%
Cleveland, OH (could only find results for Cuyahoga County): 68.5
Milwaukee, WI (city, not county): 84%
https://chicagoelections.gov/en/election-results-specifics.asp, https://www.stlouis-mo.gov/government/departments/board-election-commissioners/documents/election-results/upload/Nov20-Final-Unofficial-Summary.pdf, https://boe.cuyahogacounty.gov/pdf_boe/en-US/ElectionResults2020/nov2020/11032020UnofficialResultsbyPrecinctTotal.HTM, https://mkecitywire.com/stories/564495243-analysis-seven-milwaukee-wards-report-more-2020-presidential-votes-than-registered-voters-biden-nets-146k-votes-in-city
note: the city of St Louis is it's own county level unit, and this is what I am showing. Do not confuse this with St Louis County which is outside of the City. Super confusing.