I just returned from a 2.6 mile jog and walk. The temperature during my run was about 34 (F), and my four layers kept me nice and warm. There was no wind during my run. I left home after the sun had set but before it was dark. By the time I had run 1/2 mile, it was dark. I saw one runner and two cyclists on the path. All three had bright LED lights turned on. I got back about 7 pm.
I like to run without lights, because I can see the path better. There are buildings with lights on about 1/4 mile away, so it isn't difficult to see the path. No motorized vehicles are allowed on the path, so there is no likelihood that I will get run over due to the darkness. Well, I guess there is a slight chance I might be hit by cyclists, but they usually have lights on their bikes and can see me. I can tell they are coming due to their lights shining on the path, and I make sure I'm on the edge of the path while they pass by. The same goes for other runners and walkers. When it is dark, I usually run in the middle of the path where the probability of pot holes is low and I have more room to maneuver in the darkness.
The following picture of darkness was taken from the web. The picture shows what nighttime running is all about.