I don't usually think of J. Press as a purveyor of real casual gear (I'm talking even more casual than traditional sportswear), but their new jersey knits look quite nice. With an obvious nod to nautical styling via the stripes and colors, though I am feeling the more unorthodox red colorway the most, these made in France numbers would do wonders for your warm weather kits. I love the idea of wearing a breathable, light knit when it's nice out and, more often than not, nautical inspired pieces are at the top of my list. The long sleeves even come equipped with boatnecks (bateau necks), which is a wider neck originally designed so that sailors could easily take off their shirt when wet. With strong price points ($79-$110) these are a solid alternative to some similargarments popping up this time of year.
[Editor's Note: Mister Crew surmises these are made by Saint James.]