Vehicles pass through the heavy fog and air pollution that cover Skopje valley in the early morning, in Skopje, The Former Yugoslav Republic of Macedonia, 14 December 2017. According to media reports, Skopje is considered one of the most polluted cities in the world. (Photo by Georgi Licovski/EPA/EFE)

Palestinian demonstrators take cover during clashes with Israeli soldiers following a protest against the expropriation of Palestinian land by Israel in the village of Kfar Qaddum in the occupied West Bank, near the Jewish settlement of Kedumim, on December 9 2022. (Photo by Zain Jaafar/AFP Photo)

Adorable 1-year-old micro pig George from Gower Fresh Christmas Tree's Farm in Swansea, Wales, United Kingdom on June 26, 2023 enjoys a quiet evening stroll through the beautiful lavender field where he lives. (Photo by Joann Randles/Cover Images)

This is the moment fog rolls through a valley making trees disappear as if covered by giant waves in a sea. The fog was rolling in over the sub-alpine mountain range of the Jura Mountains in Switzerland, February 2023. (Photo by Rainer Awiszus-Emser/Solent News & Photo Agency)

A protester, wearing a dress in the colours of the Ukrainian flag, is detained by security after she covered herself in fake blood on the stairs on the Festival Palace ahead of the screening of the film “Acide” during the 76th edition of the Cannes Film Festival in Cannes, southern France, on May 21, 2023. (Photo by Christophe Simon/AFP Photo)

A tourist's umbrella blows upside down as she covers from the heavy rain and high winds, while she tours the city centre, as storm Konrad hits Spain, Portugal and France, in Ronda, Spain, on March 13, 2025. (Photo by Jon Nazca/Reuters)

The moon illuminates the snow-covered Concordia, the confluence of the Baltoro and Godwin-Austen glaciers, near the world's second highest mountain the K2 (8,000 meters) in the Karakoram mountain range in Pakistan September 6, 2014. While other parts of Pakistan and northern India were flooded, Concordia in the Karakoram mountain range was covered with a seasonally unusual amount of snow. Geographically, Pakistan is a climbers paradise. It rivals Nepal for the number of peaks over 7,000 meters and is home to the world's second tallest mountain, K2, as well as four of the world's 14 summits higher than 8,000 meters. (Photo by Wolfgang Rattay/Reuters)

“Winter shapes, Moscow river”. Moscow river at this part is never covered by ice. When the temperature is very low it's possible to see a strong fog. Morning light and pipes of the oli factory creates a fantastic landscape. Photo location: Moscow, Russia. (Photo and caption by Sergey Rumyantsev/National Geographic Photo Contest)