06/19/2012 02:44 pm ET

Chicago Weather: Heat Wave Continues With More 90-Degree Temperatures

One day ahead of the first official day of summer, Chicago's heat wave is in full effect Tuesday as the city is urging residents to take precautions amid the sweltering weather.

Temperatures Tuesday are expected to climb into the mid-90s, but are not likely to top the day's 102-degree record high, NBC Chicago reports. On Monday, temperatures at O'Hare airport hit a high of 94 degrees, falling four degrees short of the previous record high of 98 degrees.

The heat index, meanwhile, will make it feel as hot as 100 degrees in Chicago Tuesday.

Though the day on its own won't shatter records, the Tuesday heat marks the twelfth day this year that temperatures in the Chicago area have surpassed the 90-degree mark. Meteorologist Tom Skilling reports that this feat would mark only the second time since 1871 that so many 90-degree-plus days were recorded by June 19.

The year's 90-plus day tally is also four times the long-term average of such days, Skilling notes.

Chicago Office of Emergency Management and Communications manager Robert Troy advised Chicagoans without air conditioning to go to a cooling center -- such as a public library or police station -- if possible -- and to take particular care of their pets, not keeping them in a parked, hot car for any amount of time, CBS Chicago reports.

Illinois residents can also cool down -- for free -- at the Shedd Aquarium, which is offering free general admission to residents of the state through Friday because of the heat wave. Wednesday, the aquarium has extended its hours of operation until 8 p.m.

Heat and humidity are expected to stay in the area through Thursday when a cold front should roll through the area.