Where did the term "cloud 9" come from?

Search: cloud nine origin

Why: My mom says it.

Answer: Supposedly, it originated with the US Weather Bureau, which describes (or once described) clouds according to an arithmetic sequence. Level Nine was the very highest cumulonimbus, which can reach 30,000 or 40,000 feet. In the 1930s, examples showed numerical variety, including Cloud Seven and Cloud Eight and Cloud Thirty-Nine.

The current phrase is said to have been popularized in the 1950s by the CBS Radio show Yours Truly, Johnny Dollar. Whenever the hero was knocked unconscious, he was transported to "Cloud Nine."

Source: WorldWideWords

The More You Know: Johnny Dollar is described as a "fabulous freelance insurance investigator with the action-packed expense account." Exciting!