Just travelled through Sheogorath and suddenly it began to snow? Is any mod known to mess up the weather that way?

Are you using Fliggerty's Almanac mod, or anything at all like it? I use it and in the Tamriel winters I get snow as far south as Balmora. I am not certain about Seasons, but it might also make it snow in the Sheogorath region. Or perhaps the Mad God has possessed your computer, and is just making it happen cause... well... um... You know he's mad.

Seriously a posting of your load order/mod list might be handy for figuring out the issue.

I have only installed a bunch of beautifications, like trees, groundcover and such, so mainly texture and mesh replacers, that's all. How can I export my load order?

I usually just copy it from the ini, or from Mlox. I'm sure you can also get it copied from Wrye Mash too.

I'm not certain about the exact proper procedure that they want you to use here, the last time I had to copy my load order was back when the PES forums were still up.

Well, that's already all active plugins atm. Maybe I will just disable them one after another and check if the snow disappears.

GameFile0=Bitter Coast Sounds.esm
GameFile1=Bloodmoon.esm
GameFile2=Kinder von Morrowind.esm (Children of MW)
GameFile3=Morrowind.esm
GameFile4=Texture Fix 1.9 DV.esm
GameFile5=Tribunal.esm
GameFile6=abotBoats.DV.esp
GameFile7=abotGondoliers.DV.esp
GameFile8=BCSounds DV.esp
GameFile9=Better Beasts.esp
GameFile10=Better Bodies.esp
GameFile11=Bitter Coast Sounds.esp
GameFile12=Expanded Sounds DV.esp
GameFile13=Pond_scum_fix 1.0 DV.esp
GameFile14=Silt_Striders_Are_In_Vvardenfell_DVC.esp
GameFile15=Vality's Bitter Coast Addon_DV.esp
GameFile16=Vurts Aschland DV.ESP
GameFile17=Vurts Bitterküsten B?ume DV.ESP (Bittercoast trees)
GameFile18=Window Lights.esp