I remember this issue a few years ago. It’s not just how good the weather is a certain day it’s the consistency. I remember they wouldn’t open the roof in because it was projected to be colder for the next game. And both games were played on sunny days indoors when it was 70 plus. Tomorrow and Sunday look good but a projected Game 5 looks cold.
I remember the reasoning being very stupid and a lot of people arguing about it. It’s no secret the vast majority of fans want it done to be open, Apparently it only needs to be 15C to have the roof open where they would feel comfortable without any issues.