I know it looks a bit heavy, but I always thought shorts with coats are perfect together. They complete each other, and it turns into a statement outfit. Plus, it keeps you warm at night.
You can totally make the outfit more casual by wearing a leather jacket and sneakers. A white shirt and a pair of shorts is a very adaptable attire. It's the basic idea, then all you have to do is change the accessories and the shoes.
Coat HERE | Shorts (similar) HERE | Shirt HERE