Should insect screens come off in winter?

Short answer

Taking the insect screen off in winter because there are no mosquitoes is a common habit. With a window filter there is no need; it is useful in winter too.

Benefits of a window filter in winter

• Stove and chimney smoke: Soot in the air increases in the heating season; the filter holds back some of it.
• Rain: The filter keeps direct rain out; you can leave the window ajar.
• Brief airing: You need to air the home every day in winter too; the filter reduces the dust pouring in.