Monday: Chicago logs 21st day at or above 90 degrees

NOTE: This article is now an almanac of Monday’s weather. We have published a new forecast story for Tuesday.

It was another hot, humid day across the Chicago area with highs reaching the low, and to some cases, middle 90s.

Monday’s heat marked the 10^th time officially at O’Hare International Airport that the mercury has reached at least 90 degrees this month, above the typical July which sees around seven 90-degree plus days. Despite a few localized showers and isolated thunderstorms that popped around lunchtime into the afternoon, we managed more than 70% of the day’s possible sunshine.

Monday afternoon peak heat indices passed 100 degrees in many locations due to the combination of 90 degree plus heat and high humidity.  

Monday Highs across the U.S. 

Monday marked the hottest day so far this summer across the Lower 48! More than 261 million U.S. residents broiled in temperatures at or above 90 degrees. The average high temperature across the country was 90.5 degrees, warmer than at any other point so far. 

Monday High Temperature Departures

Above normal temperatures dominated the scene from the Plains east to the Northeastern U.S.

Updated 90-degree tally

Both major airports have tallied 21 days at or above 90-degrees, a number that exceeds the normal for an entire year officially at O’Hare Airport. 

Climatological Summer Update

The 77.0-degree average temperature since June 1^st is not only about 3-degrees above normal, but it ranks 2^nd warmest on record since observations began on the south side in 1928.  

Monday Pollen Count

Mold continues to be a nuisance for allergy sufferers. The warmth and humidity is helping to fuel the high levels of mold.