Sure, Summer is over but for the sake of your health, GET OUTSIDE!
This is just a quick and short encouragement to go ahead and get outside. For a lot of folks, the end of summer can be disheartening. Personally, I love Fall and I even love Winter... yup, I'm an anomoly! The key, I think, is to embrace the season your in (this includes life seasons too) and find activities that lift you up during that season.
I would recommend just getting outside. I'm in recovery from prostate surgery and have been home-bound for a week and just today I went for a walk. Oh man, just breathing that fresh air and feeling the crispness of the Fall air on me was so encouraging and uplifting. Nature has a way of doing that for us. It is actually scientifically proven that being outside and, especially, in green areas, does a lot for us both physically and mentally. So, go for a hike, a walk, hug a tree, rake some leaves, go feast your eyes on flowing water! You'll be glad you did!
"Don't hibernate... that's for bears, not you!"