I run every night during the week. I only run about 2.5 miles though. Last night the temp. was 4 degrees, very cold. The first half mile, I thought my face would freeze, but after that, I warmed up and did fine. The temp here at night has been averaging about 20 degrees most nights. I kinda like it better than hot weather. I wear long jons, sweat shorts, windpants, a Tee shirt, sweat shirt, wind breaker, heavy ski gloves, and my wool ski hat. The hat does the trick in staying warm. I always come home with a good sweat going. My face was even sweating last night.
I wish I could run 5 miles....I think my knees would give out after a few days of that, though.