Is it Ever Too Cold in Billings to Wear Shorts?

Before I get started, please understand that I grew up in a cold weather area much like Billings. I have dealt with bone-chilling cold, snow and ice storms.

When winter came around, I couldn't go without long pants and a coat. As far as I ever saw, my neighbors were the same way. Not much has changed from that time except for my location and my neighbors.

When the weather is cold, I get cold and I wear a coat and long pants.

These past few weeks or so has had me confused though. I have been chilled to the bone on a good number of occasions and on a good number of the same occasions I have seen people around town wearing nothing but shorts and a T-shirt.

Just seeing these people like this makes me even more cold.

I don't get it. I strive to stay warm and these folks walk around like this and the cold doesn't seem to bother them at all. Am I missing something? There is no way whatsoever that I could go around in a T-shirt and shorts this time of year. I would die after stepping one foot out my front door.