The FEMA advice goes into this in detail. Basically, it all depends upon yield and altitude, but there's often a pretty large zone with moderate to minimal dam

The FEMA advice goes into this in detail. Basically, it all depends upon yield and altitude, but there's often a pretty large zone with moderate to minimal damage but with significant outside radiation hazard for several hours A lot of those hazards, too, like downed wires-- are worse when you're outside. Basically, absent fire or imminent structural collapse, you should stay in place after a nuke and await some kind of orderly, systemic assessment of what's going on.