A heat index record: It felt like 120 as Chicago area sees first 100-degree day since 2012

It was officially the hottest day in 11 years for the Chicago area, and at one point it felt the hottest ever.

The weather station at O'Hare International Airport recorded a temperature of 100 degrees at about 3 p.m. Thursday, marking the first time the thermometer there has hit triple digits since July 6, 2012, when it reached 103, according to the National Weather Service records.

The heat index also hit 120 degrees at about that time Thursday, marking the highest observed level for that reading ever in Chicago, meteorologists at the Romeoville office noted.

The previous high was July 13, 1995, with a 118-degree heat index, according to National Weather Service data.

The highest recorded temperature for Chicago is 105 degrees, set July 24, 1934.

Weather data also shows there have only been 65 days since 1887 when Chicago's official weather station recorded triple-digit temperatures.

The temperatures tapered off - back down to the mere mid-90s - in the late afternoon, and finally into the 80s before sundown.

The heat is supposed to subside more at night and into Friday, when the high is expected to be in the upper 80s. The temps are projected to top out in the 70s this weekend.