Cold Februarys as a way to suppress voter turnout (in Chicago)
One of the negatives of the Progressive Movement was its focus on limiting popular vote, out of an idea that ethnic voting blocs were being manipulated in ways counter to good government.
In many places, the scheduling system for local elections were changed--usually to the Spring--and disconnected from the national election cycle. This reduced turnout but was justified out of the idea that people who voted would be motivated and knowledgeable.
A related practice is to hold local/state elections in odd years, rather than the even years when national elections are held. For example, Virginia does this with state offices (Governor, Lieutenant Governor, Attorney General, State House and State Senate), New York City does this with its local elections, etc.
Another technique to reduce the impact of voting blocs was to shift to at-large voting rather than having council districts, again, to limit the impact of minority blocs of various sorts. OTOH, some argue that having at-large districts makes it easier for elected officials to vote in favor of tough decisions, which can be hard to do when elections are district-based and it's somewhat easier to vote out incumbents.
These are still issues today. Herndon, Virginia is being blocked in its effort to move its municipal elections to the same cycle as national elections ("Va. House effectively kills bill moving Herndon elections," Washington Post) and Hispanics in Anaheim, California complained about how the at-large councilmember system kept Hispanics from winning election even though about half of the city's population is Hispanic ("Anaheim residents to vote on 2 measures that affect City Council," KABC-TV).
However, in the 2014 election, Anaheim voters approved measures to move to district-based elections and added to the number of Councilmembers.
I have to believe that Chicago's practice of holding municipal elections in February--if the winner gets 50% +1 of the total, there isn't a runoff election, which normally is scheduled for April--one of the coldest months of the year, is designed to reduce voter turnout.