Many have asked how to build a house in the exterior enviroment of Skyrim without having it rain or snow inside the house. I've copied this explanation of how I did this from an exchange i had in the forums. If you're interested in building a "No Load Doors" house, this might be of help:
Basically, I stopped it from raining in my houses by stopping it from raining in the cell that they sit in. You also have to delete the rain from the surrounding cells so that there is a transition area for the weather to slowly change and not end abruptly. This is all done in the 'World' > 'Regions' tab at the top of the CK screen. You will make a new region by copying everything from the original region you house is in. Then, you simply delete the climate that includes 'preciptation' and replace it with weather that doesnt have any rain or snow. You can also add other weather modules like fog, more auroras, or even the sky from Sovngrde.
That's what i did with my No Load Door houses (check screenshots):
Grey Ledge Manor:
http://skyrim.nexusmods.com/mods/18112

Heartwood Cottage
http://skyrim.nexusmods.com/mods/20561

If you open one of these in the CK and go to regions, you find a region with their names on it and you can see from the graph that pops up that there is a rectangle around each house with its own unique weather system.

Stopping the rain or snow from coming into your house is not easy and you'll need to spend some time learning the steps. Use a test.esp until you get it right, because one false move can delete the weather for an entire region of Skyrim. After you mess with the editor though, its real easy.

The other problem, which is really time consuming is that once you edit the region's weather, even if for a few cells, the creation kit adds 'edits' for every cell in the exterior world, which you have to go through and delete. That can be found when you open the CK, and click on the "Details.." box right next to the "Set as Active File" in the opening data screen.

Here is the page I used to learn how to change the weather and work with the region editor. It's for Fallout3 but everything is the same as the CK. 

http://www.truancyfa...ut_regions.html


Another way might be to create a trigger that activates the 'clear skies' spell whenever you enter the house. I tried but couldnt get that method to work.
But i'm not good with scripting.

There is also a mod that might help:

Rain and Snow Clipping Mod:
http://skyrim.nexusmods.com/mods/18651 hope that helps.