On the wearing of sweaters in summer
Summer offers unique opportunities for the wearing of sweaters. Heat is only one parameter in the equation, along with activity level, prevailing wind, humidity, and the possibility of day-into-night dressing on holiday. A few types of sweater are particularly suited for the warm season:
Polo sweaters, whose ribbed cuffs and hem present a sleek counterpart to generally looser summerwear—most notably when rendered in a nicer cotton with a bit of sheen.
T-shirt sweaters, preferably in interesting slubby textures, with airy open knits and boat necks to combat solar gain.
Long-sleeved linen sweaters, the kind you pull on poolside or push up to your elbows, accepting that they'll be stretched out and worn by fall. Fast-fashion brands like Zara and H&M are great for this sort of thing.