Humidity in Santee today is 68% RH and about 70 deg F, so you might get the same reading with your humidor wide open...
With small imported humidors, there is only a paper thin veneer of Spanish Cedar, over relatively non porous MDF, so there really isn't much to "season" beyond what you have already done. As long as you monitor it and add moisture as required, you are fine. When the weather heats up/dries out, you will get a better feel for how often you have to add moisture.