Winter Light: What Causes that orange Glow?

I like the light of winter-something I have noticed:in the late afternoon (>2 PM), the horizon line has an orage glow-if you are looking through trees the color is quite pronounced.
You don’t get this effect in summer-why is it characteristic of the winter skies?

Probably the low angle of the Sun in combination with all the soot from fireplace smoke. In the Summer, the sun sets much more rapidly, so you don’t notice it sitting at the horizon for so long…