With the chance of storms in the afternoon passing without real precipitation, the attention now turns to the "polar" air that will make for good sleeping weather without air-conditioning in the middle of July.
The National Weather Service expects the low temperatures to hit around 53 in the Chicago area tonight.
The service's forecast shows an even lower low in some suburbs early Wednesday morning, down to 49 in Kane County.
The record low Chicago area temperature for a July 15 is 52, set in 1967. For July 16, it's 49 in 1945.
While it'll be a cool week for July, the high temperatures still are expected to be 70 or higher.
Tuesday's forecast calls for a high of 70, as a matter of fact, with a 30 percent chance of rain mainly after 2 p.m.
By the end of the week, the high is expected to climb to the higher 70s, with lows above 60.