The humid air that clung to the Chicago area the past few days will be heading east this morning as a cold front finally moves in.
By late afternoon, the drop in humidity should be noticeable: Dew points — the measure of the air’s moisture — should fall from the mid-70s to the upper 50s.
Temperatures will peak at 85 the next five days, 4 to 5 degrees below average at typically the hottest time of the year. But southerly winds will return this weekend and continue into next week, possibly boosting temperatures to their highest levels this year.
The humid weather culminated Tuesday with dew points higher than on the Gulf Coast. Tuesday’s reading in Chicago soared to a high this year of 76 degrees at 8 p.m., then held at that level for four hours.
The reading blew past the 73-degree reading observed late Tuesday evening at Houston, Texas; 73 at New Orleans; 71 at Tampa; and 69 at Miami. A higher dew point hasn’t occurred here in Chicago since June 28 last year when 78 degrees was observed.
Tuesday’s muggy air was a week in the making and produced a string of 33 straight hours of oppressive 70-degree or greater dew points which began at 1 p.m. Monday and continued through Tuesday night.
Wednesday, by the way, marks the 100th anniversary of the world’s highest observed temperature: 134 degrees at Death Valley, Calif.