"Inspired by the East Coast’s surfing and skateboarding culture."
Two points:
Surfing and skateboarding are forms of recreation, not culture. People who suggest otherwise are trying to sell you something.
If the weather is appropriate for short sleeves, it is certainly inappropriate for a hood. People who tell you otherwise are trying to sell you a short sleeve shirt with a hood.
Cultures and subcultures can be influenced by, influence, or even center around, sports and other activities. Normed expectations of styles of dress. connected activities, speech patterns, and so on (all components of a culture) are connected with surfing and skateboarding. Regions have a role in those norms, hence the importance to note East Coast influence.
I have worn short sleeved shirts/sweaters with hoods, as well as "heat gear" athletic apparel with hoods, and found it completely "appropriate" for the context in which they were worn.
Dongmaster69Damn--that explains everything, thanks for clearing up that little mystery, Øystein!
PS: I see you don't have any endorsements yet and that you're from a foreign country, so let me lay one on 'ya in the spirt of: "I hate to see a guy from a foreign country without an endorsement!"