The answer depends on the environment that the cigar was exposed to and what protection the cigar had. Cigars often come with an individual plastic sleeve that surrounds them. This plastic protects the cigar from drying out for short periods of time. For example, on the ride home from a cigar store. A cigar with this sleeve that has been out of the humidor for a few hours, or even a day, will be not be drastically affected by the change in humidity. However, without this sleeve, the cigar, under low humidity conditions, can be ruined in as little as 45 minutes. These guidelines are only approximations, and it is strongly recommended that you protect a cigar by keeping it in a plastic bag until you can get it to the humidor. Do not tempt the fates.