User blog comment:Woganhemlock/The Sims 3: Supernatural announced/@comment-4142862-20120613082932/@comment-26744861-20120613151632

As it is in most games, weather effects are usually in the form of particle effects which if added to TS3 then it would be another thing the GPU would have to render, which may hinder load times, frame rate etc. if you're running a low-end machine. Plus the game engine for TS3 is poorly optimised and buggy. Either EA will leave Seasons for TS4 or they would have to do a lot of work on the engine to ensure things go flawlessly.