Dreams of air symbolize springtime, youthful innocence, and that you are discovering a fresh outlook on life. Perhaps you are embarking upon a new project that has you walking on air. Also, air is associated with the breath, which is synonymous with spirit.
If the air in your dream is pure, this means your spirit feels light and clean.
If the air is not unclean, then this indicates that you have been weighed down by negativity and its time for a breath of fresh air. See Wind and Spring.