This adnks101 / niks95 ~ photo contains
boater, leghorn, panama, panama hat, sailor, skimmer, straw hat, fedora, felt hat, homburg, stetson, and trilby.
There might also be
horse wrangler, wrangler, dress hat, high hat, opera hat, silk hat, stovepipe, top hat, topper, beaver, porkpie, and porkpie hat.