Just How Hot Did it Get on August 23 and 24?

​According to the National Weather Service,  it was pretty hot and humid August 23, and 24.  August 24 was particularly notable as Chicago recorded its first 100°F temperature since 7/6/2012 and also saw its highest recorded heat index of 120°F (see the graphic for an explanation on an important caveat about this).

Overview

• An expansive ridge of high pressure over the central United States brought several days of record-breaking temperatures to this part of the country during the 4th week of August.

• In northern Illinois and northwest Indiana, a brief spurt of heat and humidity occurred on Sunday, August 20th before a cold front brought some relief to the area on Monday and Tuesday.

• The worst of the heat and humidity, however, arrived on Wednesday, August 23rd and continued into Thursday, August 24th.

• Chicago officially observed a high temperature of 98°F on the 23rd at O'Hare Airport, setting a new record daily high temperature for this date. The peak heat index observed at O'Hare Airport on the 23rd was 116°F**.

• Chicago officially observed a high temperature of 100°F on the 24th at O'Hare Airport, tying the record daily high temperature for this date. The peak heat index observed at O'Hare Airport on the 24th was 120°F**.

• Chicago logged two days in a row with peak heat indices greater than 115°F, which was the first time that this occurred since the deadly heat wave of July 1995.

• Rockford officially observed a high temperature of 97°F and also recorded a peak heat index of 118°F on both the 23rd and 24th.​