Finding an apartment has gotten much tougher as many homebuyers continue to sit out a purchase of a single-family home and vie for available apartments. 

At the top of the list of 139 markets RentCafe looked at, Florida's Miami-Dade County took the No. 1 spot of most competitive place to rent during this summer's peak this year. One reason was its high occupancy rate of 97.1% with 25 renters vying for each vacant unit. The city appeals for its diverse economy and relaxed lifestyle, despite a drop in population for the first time in half a century. Perhaps, the rising costs of living and housing there are pushing some to leave. 

Among the places they may be going is to the Midwest, which now has three of its markets in the top five nationally for this same ranking—Milwaukee, suburban Chicago and Grand Rapids, Mich. Milwaukee moved into the second spot nationally, up from seventh, with 16 renters looking at every vacant unit and apartments empty being filled within one month.