Native-born Mississippian here, I’ve spent most of my life in the Deep South but also spent a year in the Northeast.
It’s hot in the summer, it’s warm and rainy in the winter. Don’t expect much snow. We get tornadoes, and hurricanes will blow in off the coast, so be prepared. Hattiesburg has a good bar scene, and there’s a really nice national park not far away. Be aware that Mississippi is infested with alligators, and they will eat you if you get close.
Religion is a BIG part of people’s lives, particularly in the rural areas but it’s still very strong even in Jackson and the other cities. I’m an atheist and I’ve managed to live here pretty comfortably for years however, so it can be done. I don’t know what faith you follow (if any) but there’s lots of churches of every imaginable sort, including Unitarian Universalist, and Catholic, Jewish, Hindu and Muslim presences in the cities. Be aware Mississippi is a very poor state, very rural. Just try to be respectful, and don’t embarass people by complaining about how rundown things may look. I’ve seen Yankees show their asses about this before, and it’s terribly offensive.
Btw, jokes about inbreeding? Yeah, it wasn’t funny the first ninety times either.
One thing that took me a long time to get used to up North was how forward Yankees were. Y’all come off as being very bold and pushy. There are some things that are important parts of people’s lives – the church, our heritage, local music. You may not understand, for instance, why some Mississippians enjoy honky-tonks or speak proudly of their Civil War ancestors; get over it. These are our treasures and we don’t need or want anyone’s permission to enjoy them.
The state is still crawling with racism, and there’s no easy way to combat it. You probably won’t change anyone’s mind by arguing with them about it, but speak up if it makes you uncomfortable to hear people saying “nigger” and such. I’ve had great success in simply telling people not to say words like that in front of me, because I find racist speech deeply offensive. For what it’s worth, there’s a lot more ethnic diversity here than we’re given credit for. Mississippi is almost 40% black, and there’s Asian and Indian communities in the cities, not to mention the long-entrenched Lebanese populations.
Learn to appreciate good Southern tea. Once you develop a taste for it, that damnyankee tea will seem like camel piss. Soul food – fried chicken, mashed potatoes, okra, black-eyed peas – is enjoyed by everyone across color lines. Dig in, and try not to worry too much about the inevitable heart attack at age 45.
Visit New Orleans as soon as you get a chance (there’s a cheap hostel there called India House you should check out) and go down to the Gulf Coast. You can probably manage a bigger trip to Florida too, if beaches are your thing. If you’re looking to party, go to Cajun country down by Lake Charles, Louisiana. Those coon-asses party harder than New Orleans, if you can believe that.