Magnum doesn't really have a problem with wet surfaces or rain, unless it's really pouring. Not that he wants to stay out there long, mind you.
Lenora's story reminded me of a very cold (-3 degrees F, with the windchill way colder than that) day this past winter. I put Magnum's boots on for our morning walk as usual. As usual, he had them kicked off about half-way through the mile walk (with me gathering them up as they came off). Once they were all off (with Magnum grinning from ear to ear, "Got'em off again, Mom! This is a fun game!"), he very quickly started lifting one paw after the other off the cold, frozen ground for a few seconds at a time. Finally, he plopped down in the middle of the dirt road, all four paws tucked beneath him and refused to get up. I had to carry him (all 27 pounds) back to the house a 1/2-mile away. He just wouldn't let me put those boots back on! As he was tucked up in the middle of the road, he looked at me and seemed to say, "I am not moving one INCH! You can't make me! You are tryin' my patience! First you put those sillly boots on my that I gotta get off and now THIS!"