![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRFc6e5oSOaZ0vIyLm18sFge3XvBObk-lLOohlAKoHq82fxb4MSn8KVqgi77d2nZRwAf4KZhNZkbiDSt4BZ0w1CQVYdTuElz6KEXNz4r8D1pXZ_CpEBEpx_xGTn7-cmoxpyPCamX7B1lA/s320/FireRainbow02.JPG)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgOpuNw9jGvJPvrMeqp0u9GkcZdCFsjUvCXQwGKME0B740FXoaZOA9oDrgddY4IwzZLUWDY8liYOjEFROPLhQh-qW4a5qvBkFsKBamLHn6KQVJ4-bBy4fbL142WIUSgQ4P8FOKpKfNT1f0/s320/fire-rainbow01.jpg)
A circumhorizontal arc (also popularly called fire rainbow) is a rare optical phenomenon. In order to be observed, the sun must be very high in the sky, at an elevation of 57.8° (90 -32.2°) or more, and can only occur in the presence of cirrus clouds. As a result it cannot be observed at locations north of 55°N or south of 55°S, although occasionally at higher latitudes from mountains.