This happens because the warm and humid air holds more moisture than cold air. When the air touches the window, it cools down and the excess moisture collects on the glass, eventually enough collects to drip down.

I'm guessing you don't have some sort of AC/central air which would help reduce the air humidity.

Better insulated windows would help, but likely isn't an option.

So you'll want to try to dehumidify your warmer air. Most likely with a dehumidifier.