Originally Posted by Doug5150

The purpose of bicycle chain lube is not lubrication, it is to prevent the chain pins from rusting and falling out.
The chain pins are a rather high-carbon steel, and they corrode very easily. And they must fit into the chain side plates very tight, or else they will tend to work out.
So this is the reason for "wet lube during wet weather". The wet oil is necessary to prevent water corrosion.

The best method is to re-lube every week or so that the chain is wet often, since all liquid oils will absorb moisture and decompose.
It isn't necessary to clean off all the old lube completely, just dump some more on. The old lube solidifies and works out anyway.