I don't remember the year, not worth the effort to figure it out, but they finally lost the horse track in the early 2000's. By then, everyone could fit inside the air conditioning, but many chose to sit outside.
It got worse at the next place. They moved to the outdoor baseball stadium where the Chicago White Sox played. There was only a handful of indoor skybox seats which were only for the Bethel/Watchtower elite- don't tell me there isn't such a thing. The shade moved throughout the day and you had to have an umbrella, but of course you didn't want to obstruct someone's view with your umbrella (what was there to see anyway?).
Many had to sit in the steep upper deck, which even the baseball fans complained about.
Everybody hated this venue, but Watchtower had a 3-year deal and stayed the entire time. I knew a few elderly people who vowed never to come back there after the first day or after the first year.
They are indoors again, in a college basketball auditorium way out in the boondocks. It's far enough out there to really make a long day driving out from the city, but not far enough to justify the expense and bother of a hotel room, unless you have to be there early to kiss up volunteer. Be sure to bring some decent cushions of your own to any of their events because anyplace other than their own assembly halls was not meant for anything more than 4 hours.