fogged up headlamps

I've noticed that the glass (or plastic?) headlamp housings often get some "mist" built up inside them.... condensation, with funny patterns in them sometimes. Both housings, toward the center of the car near the grill (basically the mist covers where the turn signals are) and also a little up on the outer corners (away from the grill, where the glass "sweeps" to a point along the fender).

Is anyone else seeing this? Is it normal?

Thanks,
- Matt

Mist seems to be cleared up after a couple of nights in the garage... I guess this is normal?

Okay, the manual goes into quite a bit of detail explaining that this is normal. (Found starting on page 134 of my 2013 FFE manual.)

Over the last few days, I have seen the condensation come and go.