Originally Posted by
The Man in Seat 9A
Weather delays in the middle of the country in the summer are normally a couple of hours, and St. Louis is not that bad. I would not worry about it, it is rare that it gets disrupted that badly.
There are also seven Amtrak trains a day from St. Louis to Chicago that take five hours and cost about $25. They run rain or shine, generally speaking.
Yes, but Amtrak would drop him/her off at Chicago Union Station downtown so the OP would have to make his/her way to ORD from there. Taxi/Uber would be best with luggage. Trying to get to the CTA Blue Line to get to ORD by subway is not an easy walk with luggage and not safe if at night.
Weather is unpredictable in the Midwest in the summer but odds are you would be fine. But keep in mind that the weather anywhere between STL and ORD will affect flights between the two. A common storm pattern is bad weather rolling in from the west, south of I80 and moving to the northeast into NW Indiana. That pattern often results in ground stops even if there are no direct impacts at ORD or STL because assents and descents would be going right through the storm. But delays are usually only a few hours unless there are cancellations.