PHOTOS: Rare 'fire rainbow' lights up sky at Pinnacles National Park in Salinas

You don't see this every day. A man running in Pinnacles National Park in Salinas on Tuesday spotted a "fire rainbow" lighting up the sky.

He's friends with a meteorologist at the National Weather Service, who was thrilled to tweet out the picture along with the technical name of the phenomenon: circumhorizontal arc.

"They're unusual," said NWS Bay Area meteorologist Roger Gass. "My friend has only seen one once, and that was in Yosemite."

The rarity of the phenomenon depends on where you are, according to Atmospheric Optics. At medium latitudes in much of the United States, the special rainbow can be seen several times each summer. In contrast, further north in much of Europe the circumhorizon arc is a rarity and impossible to see north of Copenhagen.

Technically, fire rainbows occur when the sun is very high in the sky. Near noon in mid-summer is usually the best time to see the bright colors surrounded by a halo.