This is more a question on how realistic/detailed they made it, not entirely about the way it looks. I would also like to add that I haven't yet played the game.

What kind of rain does it have, and how does it work? I know I'm hoping for a lot, but do physics objects (Stuff you can grab. Bodies, long planks, etc.) block the rain? I doubt it, but do droplets drip off of surfaces? Do puddles form? Do surfaces not hit by rain not get the shine effect on the material? Does the texture change from rain depend on the material (Concrete doesn't get shiny, but metal does)? Does rain affect the player model (metal armor shine, cloth armor drip)? Do bodies of water ripple and bubble? Do streams form in gutters? If so, do they get blocked off by physics objects? I know in the past it has been simply a visual effect. Kind of an overlay. Is rain different now?

These are probably crazy questions. Walking home in the rain got me to thinking about accurate models of rain and dynamic weather, and as a particularly large piece of hail hit my head I got the funny idea that Fallout 4 might feature some of it. This is the kind of thing I'd expect from a high quality animated film. I'm sure all of this would be absolutely insane to render. Rendering liquids in Blender has always killed my computer, so I can't imagine what rendering half of this stuff in real time would do.

I suppose this one is a simpler one: Does wind exist?

Does it affect physics objects? Does it affect the environment? Is it blocked by the environment? Is it blocked by large physics objects? Does wind affect weather patterns? Does it affect bodies of water?

Interesting thing and sorry if you havn't played yet it is a bit of a surprise but there are radiation storms. Got an interesting visual and gives you rads. Other than that i heard this morning that much of the weather is just a visual filter over your view. There are no rain drops just spots on your lense. As such pretty sure there are no puddles or wet surfaces. Many buildings are 'outside' and have holes in the roofs anyway meaning it rains in them and they dont protect you from radiation storms.

After thirteen years, precipitation is finally properly blocked by geometry. Truly it is a miracle.

As for everything else, uh... Bethesda said there's wind that affects foliage and cloth and hair, but I haven't really paid attention enough to detail it.

I remember hearing about the radiation storms before the game came out. It makes me very happy to know those are in the game. It's interesting, though, that most buildings don't protect you from the radiation or rain. Does the rain seem to go specifically through the holes? Are there caves/alcoves in mountains you can take shelter in?

Is it blocked properly by physics objects' geometry? Bodies, dropped weapons? Does rain appear to hit NPCs? I'm very curious about what exactly they did.

Finally found the quote I remember reading from Bethesda: "When a rain storm rolls in, our new material system allows the surfaces of the world to get wet, and a new cloth simulation system makes cloth, hair, and vegetation blow in the wind."

I'm curious as to how far they went with this, though. I've seen screenshots of character creation, and the hair didn't seem to be very high quality. Does it just kinda shift in the wind? The cloth blowing in the wind sounds amazing. I wonder if that also applies to most cloth on clothing. This also makes me wonder if it's just an animation based on direction character is pointing from wind or if they do physics calculations. Did they set it up so that standing behind a large building or on the opposite side of a hill would show little to no wind effects?

There's an insane amount of calculations they could be doing, but most of them would also cause an insane amount of frame drop. Most of what I've heard them brag about is just god ray graphics, so I presume that accurate weather physics aren't the focus, and instead all the new features on the engine are there for the sake of beauty. The wet materials and god rays can all be easily seen by every player, whereas accurate rain and wind wouldn't be seen by anyone except for those looking for it.

There's no realistically encounterable circumstance under which that would be relevant or even could be tested.

There's no impact effect for rain that I've noticed, other than the animated texture applied to water.