Well, for me this is a no brainer. I would have to say that the book that I have read that reminds me most of summer is “Gidget “. I read it during the summer — I remember laying on my bed with the blue floral bedspread, with the windows wide open in the sweltering Texas heat because we had no a/c reading “Gidget”. Of course, the subject matter was “summery” because they were on the beach in California!
I have to say that while I did read during the summer, I did the majority of my reading during the school year and even now identify reading with curling up on a cold day and getting lost in whatever I am reading.