fog

The Canary Wharf financial district and central London emerge from morning fog in this aerial photograph released by the Metropolitan Police in London

Metropolitan Police/Reuters

The Canary Wharf financial district emerges from Thursday’s morning fog , with central London in the background

Fog covers the valleys in front of the Alpine panorama pictured from the Auerberg mountain near Stoetten, southern Germany.

Karl-Josef Hildenbrand/AP

Fog covers the valleys in front of the Alpine panorama pictured from the Auerberg mountain near Stoetten, southern Germany

Fog rises from the valley and the church...Fog rises from the valley and the church of Marktoberdorf, southern Germany, as in background can be seen an Alps panorama on January 19, 2014.       AFP PHOTO / DPA / KARL-JOSEF HILDENBRAND / GERMANY OUTKARL-JOSEF HILDENBRAND/AFP/Getty Images

Josef Hildenbrand/AFP

Fog rises from the valley around the church of Marktoberdorf, southern Germany.

Villagers walk home carrying water collected from the Kuakhai River in on a foggy morning in Bhubaneswar, India, Thursday, Dec. 19, 2013.

Biswaranjan Rout/AP

Villagers walk home carrying water collected from the Kuakhai River on a foggy morning in Bhubaneswar, India Read more

Soccer goal posts are seen in the autumn mist at Dukes Meadows in Chiswick, west London...Soccer goal posts are seen in the autumn mist at Dukes Meadows in Chiswick, west London November 13, 2013. REUTERS/Toby Melville

Toby Melville/Reuters

Goalposts in the autumn mist at Dukes Meadows in Chiswick, west London, early on Wednesday morning. Read more

Morning fog covers the view to sail boat...Morning fog covers the view to sail boats that anchor at the river Elbe in Dresden, south-eastern Germany. AFP PHOTO / DPA/ ARNO BURGI    GERMANY OUTARNO BURGI/AFP/Getty Images

Arno Burgi/AFP/Getty

Morning fog covers the view to sail boats that anchor at the river Elbe in Dresden, southeast GermanyRead more

Sunrise Over The Somerset Levels...SOMERSET, UNITED KINGDOM - SEPTEMBER 04:  The dawn sun begins to clear the mist and fog lingering in fields close to the city of Wells on September 4, 2013 in Somerset, England. Parts of the UK are set to enjoy a late summer heatwave today, with temperatures possibly reaching 28C in central, eastern and southern England, with temperatures predicted to climb even higher tomorrow.  (Photo by Matt Cardy/Getty Images)

Matt Cardy/Getty

The sun begins to clear the mist and fog lingering over fields close to the city of Wells in Somerset, England.