@windwalker From the list of MAC hot spots, we probably can deduce that heat and humidity are not the determining factor for the existence of MAC, as these states have varying climates. Some hot but not humid, some hot and humid, some have cold and damp winters some do not. Wisconsin may get humid in the southern portion of the state in summer, but its winter is cold and dry. So far, I have not been able to find any source that would explain to me why there is concentration of MAC in some places around the country. I guess if people decide to move, stay away from the MAC hot spots is a safer way to go, although one's physical condition being another determining factor may or may not allow them to completely escape the possibility of being infected by MAC.