The puppies were doing fantastic with going outside using the doggie door until they figured out it was raining.
how much time do you spend out in the rain with the dogs? Is there any reason for them to think it is fun, pleasant or a good deal of fun to get wet?
All I know is when I make a concious effort to make being outdoor in the rain fum for the dogs I don;t have that problem back slide on the training an the occasional accident will creep in. Dog learn form our behavior as well. If you make being out in the rain fun that will transfer ocver when the need to pee/poop when it is raining as well