Football is a masculine game of sacrifice and perseverance. The northeast has a lot of effeminate secular liberal types who don't believe in sacrifice and perseverance. The south is the Bible belt they like football because they they think that will help you become a man. Many in the northeast don't even think there is a difference between men and women. The south also has more black people, 70% of NFL players are black. Also the blacks are more well behaved and disciplined down south because of the strong religious culture. The blacks in the north have no self discipline, manners, or morals. I am black so this not racist. I have seen many blacks that were tremendous athletes that had to be kicked of the team because they wouldn't listen to the coach. Down south, young black men say "Yes sir." and "No sir" when the coach or somebody in authority tells them to do something.
This has to do with culture not weather. The Midwest has bad weather but they produce football players because they are not as secular and effeminate as the northeast.