Steer away from business casual. You're not an Employee yet! While a suit probably isn't a bad thing, it probably won't make-or-break the interview. Given that it's summer, and especially in Florida, I'd go without. What's important is that you look good and feel comfortable in the clothes you chose to wear to the interview--it's just one more way you can show and feel your confidence, and it will be noticed!
When I interviewed in the People Department last year for an intern position in Maintenance Material Purchasing, I wore a blue button-down with darker blue pinstripes, just a little on the bold side, and dark navy dress pants. I pressed my clothes and sharpened all the creases. I wore a tie that was perfect. It was what I like to call a "fun" tie--you know the type--but this one had vintage airplanes and bright, florescent-colored bag tags that were reminiscent of the days before Southwest used thermal printing for bag tags. And, of course, I wore dress shoes and a belt. I left the jacket at home. The overall impression was smart. I looked like I put some thought into what I was going to wear (and I had), and the interviewers sensed that. I was later told that the tie was a great complement, as it showed care and concern enough to wear a tie, but also that I was comfortable enough (even in the interview) to be myself, have fun, and not take myself too seriously.
To top it all off, so to speak, when the recruiter called me in from the waiting area, I donned one of the inflatable airplane hats Southwest sometimes gives out as promotional items at events they sponsor. Of course, I had prepared for it and had the hat already inflated and waiting under my seat for just that moment. The recruiter paused a moment, smiled, and began laughing hysterically. Everyone I passed in the hallway to the conference room where the interview was to be held were looking and smiling, and some were even poking heads out of rooms to get a better look. When we got to the room, the recruiter asked me to wait outside the door just a moment. Then she stepped in and said enthusiastically "Guys, wait 'til you see my little Intern!" I should have known then I was as good as hired. As she led me around the corner, the whole room lit up with smiles, cheers, and laughter. After a minute or two, I politely told the room that I was going to take the hat off, since I wanted the interviewers to be able to take me seriously, and we got down to business, but not before I was made to promise that I wore the hat out of the interview and back through the People Department on the way out. Turned out to be the best icebreaker I ever could have come up with, and just the Spirit and attitude Southwest was seeking out.
Now, considering that my interview was only for an intern position, I'm not saying that you or anyone should try to be the funny guy, especially if it's any sort of group interview. But it worked for me, and when I go back to Southwest for a permanent, full-time position, I'm going to wear the hat to my interview again, even if just for good luck.
Southwest LUVs when their Employees can stand out in a positive way, either to internal or external Customers, and I think it's especially true for Employees on the front-line. If you can find good balance in standing out and making a great impression--something that will have you remembered in a good way long after your interview--don't be afraid to show it! You can't fake anything if you're genuine, so be yourself, and be honest. If any part of the interview takes on a group setting, be sure that you listen to others, contribute to the group, and that you have at least as much concern for the success of your fellow applicants as your own. In these scenarios, interviewers will be looking for that. You'll be working as part of a team at Southwest, and more importantly, a Family: not just on your own. So why should the interview be fundamentally different?
Now, since you've been given every imaginable piece of advice out there and are probably more in doubt than before, I'll leave you with this: If I've learned anything during my time with Southwest, it's that common sense and good judgement go a long way in developing effective relationships, and it's manifested in the way we choose to do business with Customers, Vendors, Buyers, and our Employees. Take that with you to an interview and apply it, show that you possess these, and you'll do just fine. If you're willing to work hard, follow the Golden Rule, and have FUN, then you can expect a very rewarding Southwest career. Welcome Onboard the Flight of Your Life!
Opinions expressed by "iflyswa" are not those of Southwest Airlines Officers, Directors, or Employees.