I know our school secretary is there all summer. I think maybe she takes a week or so off. She is quite busy in the summer getting all the forms in order, making sure class assignments are correct, dealing with families just moving into town (that was us 9 years ago), creating the bus routes, etc.
I know the superintendent is available during the summer as well. A few years ago, I had contacted her about the end of a program that had been announced at the end of the school year. She met with me, and another concerned parent, and the program was back, being run by volunteers, led by me.
Last year I also ran into the principal in town during the summer. He lives pretty far, so i knew he was working that day if he was a mile from the school. He mentioned that he had a lot to do.
There is also a summer program at one of the elem. schools. That is only about half the summer.
And the custodians are there all summer long as well. Doing the stuff that can't get done while the kids are there every day (moving everything out of the classroom to do a thorough cleaning, waxing floors, major maintenance).