I was randomly inspired by PeruseProject to make a list of summer reading recommendations, so here we go!
If you want some suspense and thrill with a hint of supernatural or fantasy, try the Green Mile by Stephen King or Ready Player One by Ernest Cline. Both of these sucked me right in and didn't let me go until the very last pages.
If you want to read something with a focus more on people in a summery setting, you might enjoy Maggie Stiefvater's Sinner, the sequel to her Wolves of Mercy Falls trilogy focusing on Cole and Isabel.
Water for Elephants by Sara Gruen also has a focus on struggles and relationships between people and the setting is a circus, a bit more exotic than your average let's-hang-on-the-beach summer novel.
The lightest recommendation on my list is the Pure Dead series by Debi Gliori, a middle grade fantasy series about a mafia family who live in a castle and own magical pets. All sorts of absurd and hilarious things happen though the family only tries to live a normal life.
Last but not least a classic summer read recommendation: detective stories. They are fast to read, keep you guessing and entertain you through and through. I personally have read Agatha Christie the most, you can't go wrong with those.