
Chicago warmed up Thursday to a degree not felt on this day in more than 80 years.
The temperature reached 83 degrees at O’Hare Airport, surpassing the previous record high of 82 degrees for April 13 set in 1941, according to National Weather Service meteorologist Ricky Castro. Before then, the city had last hit 82 degrees in 1887.
“What’s interesting about this record is if you look at this part of April, the middle part of the month, after April 10 this was one of the lower record highs that was kind of ripe to be broken at some point,” Castro said. “Being only 82 made it easy to break.”
Wednesday, when the high was 82 degrees, was the first day this year that reached the 80s in Chicago. However, mid-April isn’t an unusual time to break that threshold.
The warm weather is mostly caused by a large ridge in the North American jet stream enveloping the eastern two-thirds of the country, Castro said. Additionally, a slow-moving storm system above Mississippi is blocking off moisture from entering the Chicago area.
“The other factor that plays a role is the fact that it’s been dry,” Castro said. “Yes, we’re starting to green up, but without leaves on the trees yet, these drier air masses are more conducive to being even warmer.”
Castro said this wave of warm weather will probably have no bearing on how the summer months will fare, but he noted the Climate Prediction Center’s outlook on the Chicago summer that calls for “slightly elevated probabilities of above-normal temperatures” and precipitation.
Temperatures are forecast to remain about the same Friday and Saturday, with cooler weather expected by the lake, before dipping to “blustery and colder” weather in the 40s and 50s Sunday and Monday.