# blue hour

> English word · Noun · IPA /ˈbluː aʊə/

## Definitions
1. The period of twilight when the Sun is approximately 4-8° below the horizon and the sky is within a range of blue colors.

## Etymology
Calque of French heure bleue.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/blue-hour