Just putting this out there to help people that may have the same issue I just resolved on my PC.

After hearing about Dawnguard, I started working on a character that would fit in the more with the whole Carpathian theme more than most of my characters. So I get them to where I wanted and shelve it for awhile. Upon starting to play this specific save again a few months and mods later, I noticed a very annoying hitch in my game every few minutes that would last for about a full second. After lots of processes of elimination that I'll spare you, it turned out that my save file for that character had somehow grown to 99 megs, which was a little alarming since they're normally in the 3-12 range, give or take. After a little more sleuthing, I figured out that the scripting in the "Project Reality: Climates of Skyrim" and "Sounds of Skyrim: Civilization" mods were making the savegame file size skyrocket at a rate of 2mb per minute or so. I removed those two specific mods, then waited in-game for 24 hours so the exterior cells reset, then saved again. After a restart and running around for a few minutes, it went back to normal.

Other people seem to have also had this issue with other mods as well, such as the "Travelers and Adventurers" mod.

Hope that saves some of you the frustration. :D

I've not had those issues with those specific mods, my save files are roughly 4mbs each and stay that way pretty consistently. There are a few mods out there that can help with save file bloat, since beth doesn't really handle things well in that area (do you really need to save the state of that spoon you dropped on a road 200 hours ago?). You may be able to continue using climates if you grab a mod that helps with save game bloat.

Losing the mods was actually not that big on an issue for me in retrospect. The PR mod was cool for some areas, but a lot of the time the grass textures wouldn't shade the same as the geometry, so it would be pitch black with these almost neon-yellow/green grass effects on the ground. And the SoS mod was pretty good except the towns and cities in Skyrim aren't really populated enough to warrant the amount of ambiance it adds. I'm also pretty sure that I heard several sounds from NWN in there, which was kind of jarring hehe. I mostly just wanted it to hear the current weather outside when I was inside. Still, I'll peek for some mods to.. fix the mods...

Modception.

Hmm. I have the climate mod but haven't played enough for it to really affect me. Will keep and eye on it for sure though. Thanks for the heads up

This must be what's happening. I have sounds of skyrim and I've been wanting to punch my monitor because I keep freezing for a couple seconds randomly.