Elemental Plane of Air

The Elemental Plane of Air was an Inner Plane or Elemental Plane of the Great Wheel cosmology and the World Tree cosmology models. After the Spellplague, the Elemental Plane of Air collapsed into the Elemental Chaos, mixing with all the other Inner Planes. Air is one of the four elements and two energies that make up the known universe and therefore of keen interest to cosmologists as well as spell casters that wish to harness and wield the raw power of the elements.

Description
"It is as open as the eternal sky. Is as solid as a child's breath. It is falling forever."

- Manual of the Planes

The Elemental Plane of Air was filled essentially completely with air but had various impurities that tended to form pockets or bubbles in the otherwise pure atmosphere. Gaseous bubbles included clouds of every type, fog, steam, mist, smoke, poisonous clouds and acidic vapors; also the rare intrusion of elemental fire which is flame without fuel. Liquid impurities were usually water or water-based and tended to form floating spheres when not buffeted or frozen by the winds. Solid matter could be found here, from dust, ash, or sand, to chunks of earth approaching the size of a large asteroid. The larger chunks were often brought into the plane by intelligent beings and were very likely to be inhabited or formerly inhabited.

If you had to describe the Elemental Plane of Air in a single word, it would have been "blue". The very substance of the plane seemed to radiate the magnificent sapphire hue of a clear summer day on the Prime Material Plane. Visibility was twice what the best conditions on the Prime could allow, unless of course something obscured vision. Weather was the primary natural hazard in this plane. The winds were normally light to moderately strong throughout the plane but could intensify into tornadoes, maelstroms, and hurricanes with powerful lightning. These extreme weather events were common, and when other elements got caught up in the storm it could produce pounding rain, blinding snow, pelting hail, freezing sleet, and storms of choking smoke, biting sand, burning ash, scalding steam, or searing fire.

Inhabitants
Invisible, and yet the most common denizens of this plane were the elementals themselves including aerial servants, invisible stalkers and wind walkers. Unless magic was employed their outlines were only vaguely visible if dust or debris were caught in their bodies. When made visible, air elementals were usually large wispy beings with aerodynamic bodies and wings, or propelled themselves by forcing air through their bodies and using fins for maneuvering. Others, sometimes called animentals, mimicked the shape of Prime Material animals and monsters.

Immigrants to the Elemental Plane of Air include the djinn,  some jann, mephits of the air, dust and ice subtypes, and arrowhawks. Reported sightings of other creatures included beholders, belkers, devas, hippogriffs, pegasi, sphinxes, spectres, sprites, and vapor rats.