A sea of fog covers the Lake Lucerne near Seelisberg, canton of Uri, Central Switzerland, 13 December 2016. (Photo by Urs Flueeler/EPA)





Balloons carrying visitors fly over old temples at sunrise Tuesday, December 27, 2016 in Bagan, Nyaung U district, central Myanmar. (Photo by Thein Zaw/AP Photo)





Rays from the rising sun shine through the foliage of trees as fog covers the ground near the Guckler Karoly Observatory in Budapest, Hungary, 02 January 2017. (Photo by Balazs Mohai/EPA)





Morning mist floats above the landscape near the village of Borzonce, 228 kms southwest of Budapest, Hungary, Monday, December 26, 2016. (Photo by Gyorgy Varga/MTI via AP Photo)





A bird flies over the foggy country in Zlebe, Slovenia December 26, 2016. (Photo by Srdjan Zivulovic/Reuters)





A man takes photos of the Burj Khalifa, world's tallest tower, on a foggy day in Dubai, United Arab Emirates, Friday, December 30, 2016. (Photo by Kamran Jebreili/AP Photo)





In this aerial view the city's famed St. Isaac's Cathedral is seen in fog in St.Petersburg, Russia, Monday, December 19, 2016. The temperature in St.Petersburg is plus 2C ( 35.6 °F). Southwest warm wind caused foggy weather in St. Petersburg on Monday. (Photo by Dmitri Lovetsky/AP Photo)





Kayakers make their way through the fog on the River Trent near Holme Pierrepont, in Nottinghamshire, England, Wednesday December 28, 2016. (Photo by Neil Squires/PA via AP Photo)





Fog surrounds a small church not far from the small Bavarian village Apfeltrach near Landsberg, southern Germany, during a cold winter morning with temperatures of minus five degrees on January 3, 2017. (Photo by Christof Stache/AFP Photo)





People ride a donkey cart on a foggy day in Lahore, Pakistan, Saturday, December 24, 2016. Various cities in eastern and central Pakistan continue to experience heavy fog, disrupting air and road transportation. (Photo by K.M. Chaudary/AP Photo)





Fog shrouds the London Eye in London, Britain December 17, 2016. (Photo by Neil Hall/Reuters)





Fog covers the landscape around the peak of Uetliberg mountain (869m/2,850 feet above sea level) and the Felsenegg broadcast tower (L) in Zurich, Switzerland December 21, 2016. (Photo by Arnd Wiegmann/Reuters)





People take pictures on the mountain Smetovi as smog blankets Zenica, Bosnia and Herzegovina December 25, 2016. (Photo by Dado Ruvic/Reuters)





Sunlight reflecting off a building is seen during a foggy morning in the Canary Wharf financial district of London, Britain, December 28, 2016. (Photo by Andrew Winning/Reuters)





A man rides on a horse cart past a monument of Soviet State founder Vladimir Lenin on a central square during a foggy day in Stavropol, southern Russia December 29, 2016. (Photo by Eduard Korniyenko/Reuters)





A bus crosses Westminster Bridge on a foggy morning in central London, Britain December 30, 2016. (Photo by Stefan Wermuth/Reuters)





A man views the Big Ben clock tower during a foggy evening in London, Britain December 30, 2016. (Photo by Kevin Coombs/Reuters)





Ducks swim in the early-morning hour in a little lake in Eichenau near Munich, Germany January 3, 2017. (Photo by Michaela Rehle/Reuters)





An Indian farmer walks in his field enveloped by thick fog near Hisar, India, Friday, December 23, 2016. In the winter months, northern India experiences fog enveloped mornings that reduce visibility severely, often leading to delays and cancellation of trains and flights. (Photo by Altaf Qadri/AP Photo)





Buildings are seen in the fog in Yancheng, Jiangsu province, China January 1, 2017. (Photo by Reuters/Stringer)





A man makes his way through mist on a frost covered Greenwich Park in south east London on December 29, 2016. (Photo by Justin Tallis/AFP Photo)





The sun rises over the city skyline with the Burj Khalifa, world's tallest building at the backdrop, seen from a balcony on the 42nd floor of a hotel on a foggy day in Dubai, United Arab Emirates, Saturday, December 31, 2016. A thick fog has shrouded downtown Dubai ahead of a New Year's Eve fireworks display at the world's tallest building. (Photo by Kamran Jebreili/AP Photo)





A scarecrow is seen on a field in the rain on December 13, 2016 in Dormagen (North Rhine-Westphalia), Germany. (Photo by Federico Gambarini/DPA)