Are you serious? Tell me your jokin'.
I think he's unsure because it's north.
But the fact is that it does rain in the north too...
Also, we've seen so far that there is temperate climate, sunny weather and overcast and fog in Skyrim. All this indicates that there, pretty much, has to be rain too.
That's my "support" for coming to the conclusion that there is rain in Skyrim.
I'm definitely hoping we'll also see (hear) something similar to http://www.tesnexus.com/downloads/file.php?id=4939 so if you're in an interior cell during a thunderstorm, you can actually hear it raging outside. It makes interior cells feel much more like they are part of the outside world as you could hear the muffled thunder and rain whilst sitting inside the tavern
Ah yes, definitely this too. Would love to hear rain and thunder from inside