Hey, I did 13 miles today too!
It's been too cold recently, and I've just recovered from a week long stomach flu. But it got up to 32F today and I did a 13 mile ride on nice dry roads, and I stayed warm. It was snowing during my ride, very pretty big fluffy flakes like a picture postcard. Lucky for me it didn't stick on the road. The 13 miles was enough for me today, still not completely feeling up to par yet. After 2 weeks off my bike, my thighs are sore from the hills! Supposed to get way colder again now for the next few days, in the teens. I also walked 3 miles early this morning which felt nice.