Hi Feek, thanks, glad you like it.
As for the fog, it's already in beta. At least the very basic depth based fog. That said our current build uses the volumetric fog and it looks great, but it has some issues so I can't make a promise it will make it to the final version. My guess is there's about 80% chance it will work on PC. On consoles we have to take into account the performance impact so it will be clearer after most of the optimizations are done. Luckily most of it is computed off the main thread, so there's a chance.
Enabling and disabling certain particles is part of the weather system. It might be based on many different factors. It is already tested and we're ready to create effects like dust lifting from the roads during hot days, water dripping from roofs while it's raining or leaves falling off the trees when the wind is strong. It's one of the last layers of polish we want to make.