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)

Britain's Red Arrows airplane display team perform during D-Day commemorations in Portsmouth in southern England on June 5, 2014. Several hundred surviving veterans of the 1944 D-Day landings are commemorating the 70th anniversary of the mission on both sides of the English channel. (Photo by Carl Court/AFP Photo)

An attendee dances at the start of the “Big Goth Dance Party” during the Porcupine Freedom Festival, or PorcFest, the Free State Project's annual summer gathering in Lancaster, NH on Wednesday, June 25, 2014. (Photo by Matthew Cavanaugh/The Washington Post)

A couple watches the sunset over a sea of fog covering the Geneva Lake from Chardonne, Switzerland, 28 December 2015. (Photo by Jean-Christophe Bott/EPA)

A general view of the sunrise over Hawes, Wensleydale, UK on November 24, 2014. (Photo by Neil Squires/PA Wire)

Soldiers are reflected in a puddle during a military parade during the celebrations for Romania's National Day in Bucharest December 1, 2014. (Photo by Radu Sigheti/Reuters)

A colourful sky before sunrise on Whitley Bay beach on December 21, 2015, as December could be the mildest across a large part of England since records began more than 350 years ago, forecasters have said. (Photo by Owen Humphreys/PA Wire)

A Syrian boy looks through a gate as others wait to cross into Syria at Oncupinar border crossing in the southeastern city of Kilis, Turkey February 11, 2016.. (Photo by Osman Orsal/Reuters)