The Sims 3 Seasons was the most anticipated and demanded Expansion Pack of the Sims 3 franchise, but probably also where the community put the most pressure on The Sims Studio to better get it right! We want weather, it had to look gorgeous and would we have accepted if it did not work in every single (custom) world, with every type of house/object we have? I doubt it.
We got just that, weather that works in every world and is absolutely gorgeous. Below is winter in a few official worlds and custom ones. Besides just how awesome the weather looks, you can also interact with it. Snowball fights, iceskating (on lakes!) and getting soaked in a rainstorm are awesome in The Sims.