It's the Winter weather. My Oasis in the summer months set at 60% usually keeps the cabinet at 65%. A few weeks ago I noticed the cabinet dropping into the high 50's so I bumped the setting up to 70% which is keeping it between 68-70% which is a little wet for my tastes but I decided to keep it a little more on the wet side for the winter so should the Oasis run low I am more likely to catch it before she drops into the low 50s. I also smoke a lot less in the winter so it should not be too big an issue.
Also if you are running central heat it tends to dry out your home real well which will also effect your humidor. So it's probably more than likely the weather as this time of year challenges a lot of us anal humidity watchers.
