Rubber in humid condition

Hello,

Recently I made a short trip to SE Asia and played a bit of table tennis there. Since it is a lot more humid there compared to where I live, I noticed that ever since I returned from my trip, my rubber surface feels slightly oily even after cleaning it. 

Not necessarily a question but I just want to hear your thought on this. Would you consider this as a "damage" to the rubber or whether there are some remedy to this.

Thank you.