It might have been foggy in the Willamette Valley, but Cerridwen Martin was able to revel in a view of the top of the clouds from the summit of Spencer Butte in Eugene, Ore., on Tuesday, December 16, 2014. Martin was joined by Joe Martinson, right, for the 1.1 mile trek. Fog shrouded much of the city for most of the day. (Photo by Andy Nelson/AP Photo/The Register-Guard)

A Hindu woman worships the Sun god in the waters of a lake during the religious festival of Chhath Puja in Agartala, India, November 13, 2018. (Photo by Jayanta Dey/Reuters)

People enjoy skating at the open air Christmas ice rink on the first floor of the Eiffel Tower after its reopening on December 19, 2016 in Paris The ice rink of about 200 square metres and on the first floor of the tower (57 metres above the ground) is open to the public until February 19, 2017. (Photo by Joel Saget/AFP Photo)

A man gets ready backstage before performing in the 35th Cochin Carnival, which is held annually to welcome the start of the New Year at Fort Kochi in the southern state of Kerala, India, January 1, 2019. (Photo by Sivaram V/Reuters)

A woman waters the plants outside her house in an alley at a slum in Mumbai October 28, 2014. (Photo by Danish Siddiqui/Reuters)

A man sits waiting for a train on the London Underground in 1890, when the platform floors were still made from wooden floorboards. (Photo by Hi-Story/Alamy Stock Photo)

Tokyo DisneySea at Urayasu, Chiba prefecture, is holding Christmas festivities each night until December 25, 2012. At neighboring Tokyo Disneyland, the Christmas Fantasy parade is held twice daily at the theme park. (Photo by Disneyland)

The Royal Castle is seen a veil of heavy winter smog in Budapest, Hungary on January 30, 2017. (Photo by Laszlo Balogh/Reuters)