“CLOUD NINE – “The expression ‘up on cloud nine’ to describe a feeling of euphoric exaltation is based on actual terminology used by the U.S. Weather Bureau. Clouds are divided into classes and each class is divided into nine types. ‘Cloud nine’ is the cumulonimbus cloud that you often see building up in the sky in a hot summer afternoon. It may reach 30,000 to 40,000 feet, so if one is up on ‘cloud nine,’ one is high indeed. The popularity of ‘cloud nine’ as a catch phrase, though, may be credited to the ‘Johnny Dollar’ radio show of the 1950s. There was one recurring episode, like Fibber McGee’s famous opening of the closet door. Every time the hero was knocked unconscious – which was often – he was transported to ‘cloud nine.’ There Johnny could start talking again.” From “Morris Dictionary of Word and Phrase Origins” by William and Mary Morris (HarperCollins Publishers, New York, 1997).

The above answers are not completely correct. The original reference to ‘cloud 9’ comes from the 1896 abridged edition of the International Cloud Atlas produced by Luke Howard.

Cloud 9 was the white fluffy, comfy-looking cumulo-nimbus. Hence to be on cloud nine came to symbolise floating free on a downly, white cushion, presumably without a care in the world.

CLOUD NINE – “The expression ‘up on cloud nine’ to describe a feeling of euphoric exaltation is based on actual terminology used by the U.S. Weather Bureau. Clouds are divided into classes and each class is divided into nine types. ‘Cloud nine’ is the cumulonimbus cloud that you often see building up in the sky in a hot summer afternoon. It may reach 30,000 to 40,000 feet, so if one is up on ‘cloud nine,’ one is high indeed.

On cloud nine means elation or great.

the Xians, since it’s higher than the 7th level of hell

doctors say it when ppl undergo anestheshia..they act crazy and mental