I used to play a modified circlemud 3.0
Iirc different "zones" could have different weather, though I can't remember if the they had different day night cycles, but even if they didn't that doesn't mean you can't make it work the way you want it to.
Not sure what you are planning but I may have a bunch of old zmud maps, and I have a spreadsheet and a .TXT document with a while bunch of items statted out that I would be willing to give to you. I might even be able to connect you with someone who last hosted/ran the one I played. Would have to see if they are still around