According to Genesis, God set a rainbow in the clouds as the sign of the covenant after Noah’s Ark survived the Flood.
After the waters recede, Genesis describes God making a covenant with Noah, his descendants, and every living creature. The promise is that a flood will not again destroy all life on Earth. The rainbow serves as the visible reminder of that promise whenever it appears in the clouds.
The rainbow is therefore more than a weather detail in the story. It marks a new relationship between God and the living world after the catastrophe. The covenant includes animals as well as humans, which gives the passage a broad ecological scope within its ancient religious setting.
The rainbow also appears in other biblical passages with different meanings, so not every biblical rainbow reference concerns Noah. In Genesis, however, its role is specifically tied to the post-Flood covenant. Modern rainbow symbolism can have additional cultural meanings beyond the biblical narrative.