06 Jan 2025 - Today Santa returned to his home on Vega. Christmas trees are also gone and cannot be bought from NPCs anymore. Along with these changes, several minor map fixes have been applied (e.g. a missing stalagmite in the dragon lair was re-added, it is now not possible to levitate in that spot).
Check full changelog...
Proposal: During seasons, there could be an option to turn on/off a graphics overhaul which doesn't affect gameplay.
How it works:Simple, snow when it's cold, sandstorms in ankrahmun, rainfall on occasions. This could even be coded to read users system weather, if it's not too complicated.
Perhaps we could even get full seasonal maps if admins don't mind.
We once had an idea to create a kind of smoke/mist with fixed light effects in one place, but it was eventually not included for the upcoming update (maybe another time).
As for seasons, there was also an idea to add snow in the towns for the Christmas time, but unfortunately this version lacks sprites/borders that would be necessary to do it properly.
The actual weather effect, as you proposed, isn't an easy thing to do. It's a big task both in terms of designing and implementing in the original client.