For example many cities have outdoor Shakespeare performances in the summer. Bring your picnic blanket, some sunscreen and watch the Bard out in the elements. The best version of Othello I ever saw was when the wind was starting to howl and shriek just as the play was building up to the pivotal scene, it really stirred the blood I’ll tell you. Often the play is free if it is a performance by university acting students. I have also seen them as “pay what you can” as a way to encourage attendance (although if this is the case then definitely put in a decent amount if the performance has been good to encourage future shows).
Remember drive-in movies and how much fun they were? People have started projecting movies onto the walls of large buildings to recreate the drive-in experience. Watching a great movie under the stars is quite a magical experience and many cities sponsor events such as these so the cost to you is free. I have also seen these combined with sing-along events to classic movies like “Grease” which is a LOT of fun for the whole family.
Festivals explode in the summer. I have seen folk festivals (for music), fringe festivals (for theatre), funny festivals (for stand up comedy), corn and apple and rhubarb festivals (for food) and busker festivals (you guessed it). Lots of fun can be had at these events and it doesn’t cost anything to wander around and check it out.
So be on the lookout for all the summer fun available in your neck of the woods.