If you live close enough to one of the poles there are two times a year where it is annoyingly cold in the morning and slovenly warm in the afternoon. A half-n-half strat of shorts and long sleeve especially if being active is ideal.
It's easier to layer tops than bottoms. So shorts with short sleeves covered with a button up long sleeve can be surprisingly practical even though it feels silly. Open the button up when it starts to get a bit warm, and remove it entirely when active in the sun. Large diurnal temperature swings can mean committing some fashion faux pas.