I've noticed that some of the writers groups I'm affiliated with tend to slow down quite a bit in the summertime. Writers appear to be running straight back to their childhood school days when school let out the end of May or early June and there were "...no more books, no more teacher's dirty looks." as some sang on their way out the door. They turned their backs on schoolwork.
That's fine when you're a kid, but writers can't take an entire summer off. Oh, they can, but it's not going to be of much benefit to them in their writing world. We all need time off from whatever job we do, but the time off needs to be limited. An athlete who takes the whole summer off is going to find that he needs to work extra hard to get back to the level he was when he decided to loll on the beach and swing in a backyard hammock instead of conditioning and practicing.
Ask yourself how serious you are about your writing life. If you're only doing it for some self-satisfaction, you probably can take a summer off and not be any worse off. It's also possible that after being away from writing for so many weeks, you might not get back into the swing of it. But if you are writing with the hope of being published or making a name for yourself in the literary world, you can only afford short spurts of time off.
Summer brings many opportunities for all of us. We have more out of town company. We can be outdoors more often and longer with daylight lasting well after dinnertime. We have things to do with children or grandchildren. But it's that old story--we can make time for the things we want to do, and if we want to continue to grow as writers, we need to make writing a part of our regular schedule.
If you usually spend an hour each morning writing, cut it to half an hour if necessary--just don't cut it out altogether. If you go on vacation for a week or two, get right back into the swing of writing when you get home. Better yet, take a small notebook with you and write for a few minutes when you see or do something that moves you. Or take a journal and write something in it at least once each day. I do that when we travel overseas, and they're great fun to read years later. Things I've written while on the trip have helped me write a travel piece when we return home.
You don't have to be a kid again and take the entire summer off. You can find bits and pieces of time to write, and I hope you will.