People move for many reasons. They move for health reasons. They move for different climate. According to the U.S. census in 2000, the percentages of these two are:

Health: 1.1%
Climate: about 1 %

My grandparents were on vacation in Colorado. They loved the climate, the region, and the beautiful mountains. They moved from California into their newly built house in Colorado. They both loved it there.

My Uncle moved from Arizona for health reasons. It was too dry. He was planning to move to somewhere nice and hot in the summer and cold in the winter. So he planned to move to Colorado so he would be in the mountains where it was cold and be in the plains where it is a little more warm.