1) Nice(r) weather
I'm not really an outdoors-y person, but during the summer, I like sitting outside without wearing three layers, and I enjoy walking through my garden shoe-less. This is not possible during the fall when the grass is usually cold, not to mention muddy.
2) Music festivals
All the best music fests take place during the summer. End of summer means end of festival season.
3) The food!
Certain fruits are no longer in season once the summer ends, you can't find corn on the cob for cheap (or it's not as tasty), and, eventually, it gets cold which makes eating ice cream unpleasant (I mean, I still do it, I'm just cold both inside and outside).
1) Sandals and Pedicures
I have not worn socks in approximately 3 months and I love it. I would live in sandals if I could, especially with a nice summery pedicure.
2) The Colours
Everything is so bright and happy in the Summer, from the clothing, to makeup, to decor. As much as I love the warm tones of Fall, there is something about Summer colours that can really brighten up my day no matter what.
3) Ice Cream is Everywhere
This is probably okay that this ISN'T a concern anymore, because having constant access to ice cream is no bueno. However, it is super delightful to be able to walk down the street, sweating your ass off, and know that just down the road you can get a chocolate/vanilla twist that will make all your troubles melt away.