A SIDEWAYS RAINBOW ABOVE THE SNOW

 A SIDEWAYS RAINBOW ABOVE THE SNOW 

Not a normal rainbow .. this is a cold-sky trick.

That bright arc is a circumhorizontal arc (often called a “fire rainbow”): sunlight passes through ice crystals in high clouds and spreads into a sharp band of color. It usually shows up when the sun is high and the sky has thin, icy clouds .. the snow just makes the colors look even stronger by reflecting extra light.

You can catch this in cold, clear mountain regions like the Alps, especially on crisp days when high thin clouds drift in quietly.