When would it be too cold for a run?

I went for a run this morning, did about 3.5 miles in my hilly neighborhood in air that I think wasn't quite 20 degrees F. It was cold, but not too cold. In fact, I think I prefer running in the cold to running in the heat. Just think, its easier to keep adding layers than to take them off. I almost didn't go at first, thinking it would be too cold or that it was beginning to snow. I'm glad I sucked it up and went anyways.

Thoughts on today's run....

Saw four white-tail deer watching me anxiously from a hill. Their ears and tails stood straight up as they watched me, waiting, ready to run at the first sign of danger. After a moment they went back to eating as I'm pretty harmless.

Snowflakes floated tentatively from the partly cloudy sky. At times they seemed to almost be dancing with me as they made their not-quite direct trip downward. They clung to my eyelashes and landed, cold, on my cheeks.

My lungs burned only on the last hill home, the cold air makes me feel alive and I push it more than normal.

I was the only one on the road but for a few cars. It was quiet, peaceful.

I've decided Micheal Jackson's "Thriller" is a great running song.

My shoes have a little over 500 miles on them, which means its time for new shoes. They may have to wait til Christmas is over.