Re: Is there a way to turn off the weather entirely?

@aodoherty You can disable both rain and snow in the Game Options menu in the weather tab. You can disable the temperature effects on your Sims in the same menu. The game will still create Holidays but you can delete or cancel those in your Calendar. 

I'll check on MCCC but I don't recall ever seeing anything for disabling weather.

I hope this helps :D