בַּעֲנָנִים

The English expression on cloud 9 comes from the meteorological classification of the largest cloud in the sky as “cloud 9.” Someone so happy they’re on cloud 9 is riding on the biggest cloud possible, so to speak. Who knew?

Most Israelis certainly don’t think about this classification and simply say such a person is בעננים
in the clouds.

For example:

כשהוא קיבל את המתנה שלכם הוא היה בעננים.

When he received your gift he was on cloud 9.

A single cloud is ענן
.