That is quite literally what just happened in a game I'm in. DM started talking about this insane sand storm and boom. Air elemental and a swarm of dust mephits.

Quote from ShaydyCharacter >>

I appreciate that Elementals are resistant to damage types associated with their element, but in the air elemental's case I imagine thunder damage (which can disrupt air) and lightning damage (ionize the air) would be the first two damage types I would go to logically to attack such a thing (other than say, force damage or good old magical weapons). I mean, it's resistant to thunder and lightning, but acid hurts it fine, even if it's not magical acid? Fire, sure I guess, only burns oxygen AFAIK but not total nonsense. Cold?... Wouldn't that just make cold air? 
I can slash and stab this thing with magic weapons, melt(?) it with acid, freeze it, burn it, even whittle away at it with NON magical weapons. But if I try and scatter it's form with a thunderwave... it's on the same scale of effectiveness as stabbing it with a mundane rapier. Also, while this is a whole other conversation with balance reasons behind it and it'll still be halved, a rogue can hurt this thing with a mundane dagger or hand crossbow. 
In this regard, I feel like treating Air Elementals resistances with the standard elemental resistance template is close to the opposite of what makes sense. 
Then if you look at different thunder damage spells it get's a little trickier. If you look at Shatter, it makes perfect sense that it'd be highly effective against Earth Elementals and weak against these, but referencing thunderwave again,. one could imagine it passing harmlessly over the dense form of the rocky boy, and scattering this thing to the winds from whence it came. 
And this is why I like it when I have players that let me improvise, + punish and reward them on a case by case basic for using their noggin. 
Seeing as how I'm moving right away, I'm really nervous about trying to get new people on board with my style of play. I love DMing when I'm given the trust and freedom to run it my way.

 It makes sense if you think of the elemental as an animating force of the nearby elements. The vibrations from thunderwave simply pass though it, and the earth elementals form made of numerous small or medium sized rocks is blasted apart. It also explains the earth glide, the elemental abandons its rocky form to glide through the earth, then animates whatever earth it emerges from.

me 

Reminder that 10 Aarokocras can summon 2 of these from cover 

put one in a tank, compresss it and use it as an infinite jetpack or zeplin

LOOL my mvp player is a moon druid, so I wanna see how they do against it

My dm just gave me an elemental sapphire gem. >:)

mean wind

They’ve joined the mile high club? 

Is an air elemental invisible?

Fire elementals definitely deal the most damage of the four. Wind Elementals are the fastest, and can fly

would this be good for a level five campein?

Quote from Schoobs >>

Is an air elemental invisible?

 No. You might be thinking of invisible stalkers, which have a trait that makes them so. But air elementals have no such trait and thus can be seen perfectly fine.

I imagine they're made out of clouds, not just oxygen or something, which is why they can be seen with the naked eye.

Akamoria, Brilliant!

no

tee hee

at higher levels.(9 i think) the druid circle of the moon can wild shape into an elemental

Question: I am considering these as guards in the area surrounding The Halfway Inn, in the Greycloak Hills. I am picturing a forested area with dense fog. If so, would you rule that the Air Elementals count as heavily obscured, since they are made of air and possibly blend in with the fog? 

Imagine If you could contain them in a bottle, then release them on your foes. That genie ain't granting no wishes.

Quote from bearslord >>

woosh elemetal

 

 Yup.