|Open? This time of year??|
Well, they're not really open. The storm windows are installed, and so with the ports open, the storm windows still provide a seal against the cold outside.
And why do I have them open? Well, because it was raining when I installed them (Huh. Imagine that.), and despite my carefully wiping off the outside surfaces of the port lenses, some moisture remained trapped between the port lenses and the storm windows (you might just be able to see it in the picture). With the dehumidifier running (it's always running this time of year...) and the ports open, I am giving that moisture a chance to evaporate.
I should have made these years ago.