How should I clean and store my humidifier before putting it away for the season?

Dump leftover water, fill the tank with a 50/50 white vinegar and water mix, let it sit 30 minutes, then run it in a well-ventilated room for about an hour. Rinse thoroughly, then dry every piece completely—take the tank apart, pull the filter, and leave everything on a towel for 24–48 hours. Store it in its original box or a clean plastic bin in a cool, dry place, not a damp basement or uninsulated garage.