Q: My lovely wife tells me that proper etiquette requires me to wear my straw hat from Easter until Labor Day and then switch back to my felt hats. But early September seems way too early for felt since it stays hot until much later. Does this rule apply to Texans?Randy Hroch, New BraunfelsA: The Texanist is quite familiar with the traditional guidelines associated with seasonal cowboy-hat donnery. And yes, it is customary to wear straw hats, which are lighter and breathe better than felt hats, between Easter and Labor Day (the first Monday in September). Felt hats, which keep the noggin warm, are customarily worn the rest of the year. The observance of these dates is, the Texanist will note, a fairly modern convention. As…