http://mw.modhistory.com/download-44-9577

Apart from this one... are there any which cause penalties for rainstorms and swimming in water?

Something like the frostfall mod for Skyrim.

Did you know that MMH has a search function?


Adds dangerous Lightning Strikes: http://mw.modhistory.com/download-44-13479

These two probably conflict, as they both effect cold weather:
Temperature: http://mw.modhistory.com/download-70-5483
Icy Water: http://mw.modhistory.com/download-70-6337