Cigars stay fresh without a humidor for up to a month when kept in their original wrapper. Cigars kept in a humidor can last for years in a properly controlled environment. A humidor keeps cigars from drying out and the oils from evaporating.
Two common methods of storing cigars without a humidor are to use a Tupperware container or a Zip-Loc freezer baggie and a paper towel lightly dampened with distilled water. The cigars should be placed on the opposite side of the container and kept in a cool, dark place to ensure they do not become too humidified. An alternative is to use a humidity pack, which serves the same purpose as the paper towel.