A fog bow is a similar phenomenon to a rainbow; however, as its name suggests, it appears as a bow in fog rather than rain. Because of the very small size of water droplets that cause fog—smaller than 0.05 millimeters (0.0020 in)—the fog bow has only very weak colors, with a red outer edge and bluish inner edge.

Two ruddy shelducks fly under a double rainbow in Odisha, India in July 2022. These birds are ruddy shelduck, known locally as the Brahminy duck. They have a wingspan of between 43 and 53 inches and stand at a maximum of 28 inches tall. (Photo by Suman Das/Media Drum Images)

Ellesse Janda welcomes a spring rainbow at Cresswell in Northumberland, United Kingdom on March 17, 2023. (Photo by Ian Sproat/Picture Exclusive)

Photographer Will Evans captured this New Forest foal under an incredible double rainbow at Wilverley Inclosure near Brockenhurst, UK on September 21, 2023. (Photo by Will Evans/SnapPhotography/Bournemouth News)

Hot air balloons rise over Innes Common Park during a dawn lift on March 29, 2012 in Hamilton, New Zealand. Each Autumn over 30 hot air balloons grace the sky as part of the Balloons Over Waikato Festival. (Photo by Sandra Mu/Getty Images)

A couple covered with the US and the pride flags pay their tribute for the victims of a 12 June mass shooting in Orlando, Florida, USA, as they look at the Eiffel tower, illuminated in rainbow colours, in Paris, France, 13 June 2016. A total of 50 people including the suspect were killed and 53 were injured in a shooting attack at an LGBT club in Orlando, Florida, in the early hours of 12 June. The shooter was killed in an exchange of fire with the police after taking hostages at the club. (Photo by Yoan Valat/EPA)

A seagull flies through a rainbow near the Savannah River and the open spillway at Thurmond Dam in Clarks Hill, SC, Monday, January 4, 2016. (Photo by Michael Holahan/Augusta Chronicle via AP Photo)

Women hold hands during the Tokyo Rainbow Pride parade celebrating lesbian, gay, bisexual, and transgender (LGBT) culture in Tokyo, Japan, May 8, 2016. (Photo by Thomas Peter/Reuters)