Hats beat umbrellas as far as I am concerned. I know there are tweedy wool rain hats, and and floppy sloppy bucket/fishing caps, but what other options are there for headgear when it is both wet and warm out? Specifically, something in that business casual grey area between truly casual and truly business, say linen and seersucker. Some felt or tweed hat is too heavy, but a frumpy cloth hat is too relaxed. What am I missing in options here?