d20 does Dallas

[Shadowdancer]

Depends on the situation. If it's just for color, and we're just traveling from place to place, I don't worry about it too much. "There's been a light rain all day, takes you an extra hour or so to travel that distance" -- that sort of thing.

There have been times when they took damage from thunderstorms and hail storms, until they sought protection.

If combat breaks out, I limit their movement, and give them chances to slip and fall, drop weapons, etc., depending on the situation and the weather.

 

[Vaxalon]

In a magical world, unusual events happen for a reason.

That's the way I look at it.

If there's a three foot snowfall in the middle of summer, then something SENT it.

 

[Voadam]

I totally thought this was a thread about d20 porn.

Me too.

But back to the actual topic:

Adding in little (or big things) things like weather adds a lot to the atmosphere of a game. Characters will sometimes believe there is someone behind the storm, but let them speculate, there does not need to be a supernatural reason behind every event. Storms that make characters sit still for a couple days can be great for soem downtime activities like going over that book the party stole from the wizard's tower, or developing events to back up a character's traits such as an affable character making friends with the inn staff, etc.