Rosie will go out whatever the weather, but Ebony has gone 18 hours without a wee at home, however she enjoys her walks and she will go out in the rain, and at our caravan....it's me that won't
I believe with, Ebony, we got her in January, when it was very wet and toilet training became a nightmare. She perhaps associates our garden with being forced out in the rain. I must admit with all my other puppies I used paper, gradually moving to the door together with going outside. The new thinking is just straight outdoors. With hindsight I wish I'd used both, as my anxiety and frustration, although I tried hard not to show it, was passed onto her,not that I'm advocating it works for everyone.
As far as walks go, personally I wouldn't get too upset about him not wanting to walk in the wet, as its early days, wait for dry weather so he enjoys them and then he'll want to go.