What is the best height for grass in the winter?

It depends on where you live and what type of grass you have, but usually your last mowing before winter should be much shorter than previous mowings. For example, if you live in Ohio and have a Kentucky Bluegrass lawn, your last mowing of the season should be around 1 1/2 inches. Cutting it short reduces the chance of snow mold developing on the lawn over the winter months.