Even when the sun goes down, the heat can be brutal.
I almost passed out when we went to the first Sept party in 2022. It was so hot. We scored a really good spot for the parade & fireworks in the center hub. But as it got closer, it got more crowded around us. It was already hot but I guess with the crowds, it got even warmer. The lines for water in the hub area were ridiculous. About 5 minutes into the fireworks, I could tell I was gonna pass out. I felt so bad but we had to call it and escape up main street to Starbucks for water. We had been drinking water nonstop but it was just so hot, we were sweating it all out.
My biggest tip now is to dress comfortably & bring multiple bottles of water with you.