Yeah, I'd like if upon entering various areas more variable descriptions were given. I agree that when walking outside, being told the temperature and sky conditions would be great.
It could make interiors more alive and dynamic too. Perhaps the Lady's Rest usually warm and cozy but on occasion get hot and smelling of fear, or cold because the fire is out.
The sewers could vary in just what is smelling foul at any given moment and have a reminders about how dark it is and the necessity for a light source for most races.
Some areas already have triggered descriptions upon entering, like I believe Tigan's Rest and the Morning Lord Crypt.
Dynamic updates, such as weather would make the server more dynamic and could serve as a cue to do a little RP. I can't wait to see more PCs [shivers as evident by the light of near full moon] upon stepping outside.
I would also suggest distinct sounds be added to these descriptions, like the distant/near sound of wolves howling, wind wrestling through tree limbs made bare by winter, dishes clanking, nervous chatter of patrons, the sound of gurgling blood, the scamper of little feet fleeing.
I think it would be better if everyone got the environmental descriptions upon entering an area as opposed to needing to turn on a specific mode.