Dress for the Weather, Not the Calendar
Yes, you can wear white after Labor Day.
It's mid-fall down South. While everyone else North of the Mason-Dixon is racing to slip on their Barbour jackets, tweed, and the like, some of us are still experiencing temperatures in the high 80s, with plenty of humidity to boot. While traditionalists argue that at this point its far past time to have the whites, linens, seersuckers and such away in storage until next Spring, I strongly oppose the notion. Just because the calendar reads late September or October, it doesn't necessarily mean it's time to break out the fall regalia with careless aplomb. If it's still sweltering outside, these superfluous rules certainly don't apply.
The archaic rules for white and seersucker in accordance with dates on calendar were conceived in the early 20th century in response to upper-class WASPs vacationing in Bermuda, The Bahamas, and the like. As they returned from the tropics, it was considered unsightly to wear light-colored "resort-wear" back on one's home turf. Furthermore, as light colors and fabrics like linen and seersucker were considered inherently casual and inappropriate for wear "in town" or "in society," these rules gained precedent. During an era where men wore dark wool suits, ties, and hats daily, the rules eventually gained momentum and went beyond the upper and upper-middle class, subsequently reaching folks of all walks of life. Thus, a set of fashion principles were born that are still unnecessarily adhered to by many to this day (particularly in the South, which is the most geographically impractical region, given the warmer climate). I even recall a rather spirited (approaching hostile) debate in my freshman year English class in High School between the professor and two groups of students over the "no-white after Labor Day" rule (in the South, naturally). Moreover, unseasonably warm falls and winters as of late around the country make even more of a case as to why this practice should be abandoned. The matter of fact is, much like the switchboard operator or the kerosene lamp, the no-white/seersucker rule has its place in history, but not in the present day. There are simply too many occasions where exceptions need be made for the "rules" to be even considered feasible. Then again, some argue that rules are made to be broken...
The same can just as easily be stated about winters. While living in Boston, I found myself excited to attend Easter brunch clad in madras, sans socks one Easter after a particularly harsh New England winter, only to end up shivering while walking on the streets narrowly avoiding icy puddles and piles of snow left over from storms several weeks prior. I recall wearing grey flannel trousers and a tweed jacket to dinner last May in Boston... It was 47 degrees Fahrenheit outside that evening. According to the strict purists, I should have been sporting lightweight fabrics and minimal layers, as it was officially Summer according to the calendar. So if it's 48 degrees in April, wear that overcoat with pride! Is it 88 degrees in October? Break out those linen trousers you've been wearing all summer long!
Instead, one should seek inspiration from the British collegiate sartorial tradition of the 1920s and 30s, where during the late fall and winter, a navy blazer and white flannel trousers were a de rigueur staple for the sporting gentleman on the campuses of Oxford and Cambridge. In addition, when the mercury actually does drop, and lighter fabrics may no longer be a practical option, one can definitely still make the case for adopting “winter whites,” or white, heavier cloths, i.e. a white pair of corduroy trousers or a cream, flannel, sport coat. As the master of your sartorial domain, there isn’t really a need to be bound by constraints of the calendar with your color palette. In short, meteorological practicality in one's dress, not adherence to the date, reigns.