Winter slows down many functions. It is not just the animals that go into hibernation.
Red Stewart Airfield, Waynesville, Ohio, is one of the finest grass strip, grass roots airports you will find. Driving past many municipal airports will find little activity, but not at Stewart Airfield. There are always cars present and planes active.
But, things do slow down in winter, and grass strips in particular. Plowing the snow off can damage the runway. So, many planes sit until the snow melts. It’s a little like motorcycling.