How does humidity affect your home and your family? Humidity affects indoor air quality; for instance, when humidity levels are too high, it can spur the growth of mold and mildew. Ideally, humidity levels inside your home should range between 30 and 60% to feel most comfortable, and enjoy the healthiest air. High humidity indoors can result in not only a clammy feel, but musty odors due to mold, mildew, and other contaminants that can be a risk to your family’s health. On the other hand, air that is too dry and lacks humidity can result in dry, itchy skin, sore throat, and reduced resistance to upper respiratory problems.