A rainbow appears as people enjoy a warm afternoon on a tour boat at Niagara Falls in Ontario, Canada on October 21, 2024. (Photo by Mert Alper Dervis/Anadolu via Getty Images)

Cambodian motorcyclists drive near a double rainbow, following the conclusion of a ceasefire deal between Cambodia and Thailand, in Siem Reap, Cambodia, on July 29, 2025. (Photo by Daniel Ceng/Anadolu via Getty Images)

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.

Tokyo Rainbow Pride 2015, at Yoyogi park-Shibuya, on April 26, 2015. Some 3,000 lesbian, gay, bisexual and transgender people paraded through Tokyo’s Shibuya district Sunday afternoon to demonstrate their hope that Japanese society will continue to forge ahead with recent moves to embrace equality and diversity. In a nation where prejudice against sexual minorities persists, the annual Tokyo Rainbow Pride parade has sought to counter the trend by openly spotlighting LGBT residents and spreading their voices. But this year, LGBT participants and proponents seemed particularly joyous, emboldened by what they see as a blossoming of LGBT-friendly moves by municipalities and companies. (Photo by Yoshiaki Miura)

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)

A picturesque supercell formation in the northwest of Booker, Texas from June 2013. (Photo by Mike Olbinski/Barcroft Media)