The low 90s may not exactly spell relief, but it's enough of a predicted drop in temperature for meteorologists to declare that the Chicago-area heat wave is beginning to wane.
Over the weekend, the temperatures are expected to hover around 90 degrees, with humidity that will make it feel about 10 degrees hotter. But by late Sunday, a cold front will creep into the area, pulling Monday's temperatures into the mid- to low 80s, said Mike Bardou, a meteorologist with the National Weather Service in Romeoville.
"Don't think it is going to feel like you walked into an air-conditioned room," Bardou said. "But it will be marginally more comfortable."
On Thursday, the temperature peaked at 99 degrees around 2 p.m. at O'Hare International Airport, the city's official recording station. The heat index, meanwhile, reached 109 degrees at 1 p.m., and then began to fall as the dew point dropped.
The sweltering temperatures again drove people indoors or to local pools and the shores of Lake Michigan. In Lawndale, a couple of parents protested their local elementary school's lack of air conditioning.
"It's too hot," said Cheryl Fox, who pulled her 8-year-old son out of his summer program at William Penn Elementary School this week because the North Lawndale school does not have central air conditioning. "I feel that if one school has air conditioning, all schools should have air conditioning."
About 80 percent of Chicago Public Schools summer school locations have partial or full air conditioning, said CPS spokeswoman Becky Carroll. The school district has handed out 1,500 fans and recommended strategies to combat the heat, such as drawing the shades and turning off the lights, to the facilities without air conditioning.
Officials at Penn Elementary moved students who had to take the Illinois Standards Achievement Test on Thursday into select rooms that were air conditioned, Carroll said.
"It is our understanding that children who were taking the ISAT were being moved into these air-conditioned or cooler rooms," Carroll said.
Over the years, CPS has looked into providing air conditioning at all of its buildings, but Carroll said that the costs and logistics of outfitting the district's older infrastructure have made it impossible.
"The district simply does not have the financial capacity to fund those types of (projects)," Carroll said.
This week's stifling temperatures have been caused by an eastward moving "heat dome," a sweeping high-pressure ridge of hot humid air, rising out of the South, Bardou said.
The Chicago record high temperature for July 21 is 103 degrees, set in 1901, while the city's all-time official high is 105 degrees, recorded on July 24, 1934.