FOGs might want to correct me on this one...

The desired humidity is 65-70% - this is a relative humidity and is meant to be at a temperature of around 70-75 degrees. When you have the cigars at a lower temperature, if you want to have the same amount of water in the air (absolute humidity), you would need to raise your relative humidity up. Looking at a psych chart (at sea level) yields this:

75 = 62%
70 = 70%
68 = 75%
65 = 83%
63 = 88%
60 = 100%

So, if the intent is to have the same amount of water vapor in the air (I think this is the case) - then when you have them stored at 63 degrees you would ideally want to have the RH up to 88%.

-Buzz