The Indianola Balloon Classic is held about 20 miles south of my house, so we see lots of balloons the last week of July as they drift over Des Moines. It's not unusual to see them at other times, too. Pretty cool! A friend's son got a free ride when he worked for a local radio station. Scared him, but he enjoyed it just the same.
Regarding low flying jets as referenced above, in the late 1950s, my dad was plowing in west central Illinois, and looked back just in time to see a fighter jet about to buzz him. He said he could have stood on the tractor seat and stabbed the jet with a pitchfork!
In the early '80s, the Air Guard flew F16s and B52s in a loop from St Louis to Sioux City and back at very low altitude. Northbound, they flew directly over our farm, with the B52s going directly over our house at maybe 300 ft at all hours, day and night. This went on for months. We could kind of hear the B52s coming most of the time, but the F16s were past us before we could hear them, and they were LOUD! They generally flew a little higher, but not always. The F16s flew in pairs, and a pair flew over a bridge that was being worked on just as I approached the bridge. I didn't see them, so the noise scared the crap out of me. I thought there was an explosion on the bridge. Another time I had an experience similar to my dad's. I was unloading a wagon load of corn and had 2 tractors running plus an elevator. As I raised the wagon, I looked back to see 2 F16s coming directly at me. If I hadn't seen them, they'd have scared me big time! Despite the scares and the annoyance of the B52s in the middle of the night, we missed them when they ended the flights.