No relief from the heat as September kicks off. Is this normal?

September 1 was the start of meteorological Fall — but also the start of yet another heat wave in the Chicago area. A heat advisory was issued by Chicago's Office of Emergency Management and Communications for "dangerous heat" on Tuesday. Peak heat indices — or how the temperature feels — were expected to reach 100 to 105 degrees on Tuesday and Wednesday due to humidity. Even higher heat indices were possible south of Interstate 80, National Weather Service Chicago said on X. Is it unusual for…