Honestly, I live somewhat close to Dallas/Austin, so I was curious. http://www.nuclearsecrecy.com/nukemap/ It's a legitimate website that can show you exactly how far a nuclear strike would spread if it hits wherever you pick. Rather interesting. It shows the fireball effect, the radiation spread, the thermal radiation spread, everything. You can pick the North Korean 2013 test bomb, or any other known nuclear bombs in history.