Meaning of the word "finger in the air" in English

What does "finger in the air" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

finger in the air

US /ˈfɪŋɡər ɪn ðə ɛr/
UK /ˈfɪŋɡə(r) ɪn ðə ɛə(r)/
"finger in the air" picture

Idiom

a guess or estimate that is not based on any facts or real information

Example:
His prediction about the sales figures was just a finger in the air.
We don't have enough data, so any estimate would be a finger in the air.