HA HA HA !
You are definitely NOT alone with this !
My two absolutely abhor the rain, and dash in with the first drop they feel.
What the laughable part of this is...
When I take them out hunting/jogging along the Bayou, they'll jump in after a Frog or Snake in a heartbeat, or, lay in a puddle of water to cool off regardless of it's cleanliness.
I have to lay Potty Paper right in front of the Doggy Door, where they can potty while it's even misting. They will go out in the wet grass though, and the paper is a good blotter for their wet feet as they return.