It's probably already been said but Final Fantasy XIV has some pretty legit weather and storms. Best in an mmo in my opinion. Especially the thunder storms.
yeah thunder at night in those.... elven area (forget the name or the 'realm' name) that one forest and its rainstorms were great.
coerthas was great, too... nice flurries and snowstorms.
i think my favorite effect in ff xiv was the heat wave in southern thanalan tho...
https://youtu.be/d9ldwQFh4Uw?t=103
https://youtu.be/QOwTsohnOuA?t=44
maybe hard to see (
this is the zone with just regular sun) at 720p (what PS Share captures at) but it adds a nice blurry heat wave effect. simple, technically, but it's a real nice touch.
It's old now but the rain and snow in the original EverQuest was amazing for its time. It was more about the atmosphere and sound than anything.
The thunder and the sound of the rain felt like real life and since it decreased visibility, it made you want to go inside a building or cave and wait it out. Great stuff.
in general, I think MMOs are always great at weather because sort of design, they're about living in a world... whereas most games you maybe spend minutes, perhaps an hour, in an area before the next 'stage', in MMOs you often spend hours at a time -- maybe even days in one zone. so weather really fleshes out that sense of being there and brings it alive.
i remember even in DAOC or AO, the weather was one of the best parts... when it would snow in the Midgard Frontier, maaan I could scout and patrol those snowy forests for hours and not get bored -- just lost in the environment of the snowy mountain forest.