Elephants spray villagers with water in celebration of the Songkran water festival in Thailand's Ayutthaya province, north of Bangkok, April 10, 2015. The annual elephant Songkran is held to promote the tourism industry prior the Songkran Festival which is celebrated with splashing water and putting powder on each others faces as a symbolic sign of cleansing and washing away the sins from the old year. (Photo by Chaiwat Subprasom/Reuters)

People wearing costumes attend the annual water-splashing festival to mark the New Year of the Dai minority in Jinghong, Yunnan province, April 13, 2015. (Photo by Reuters/China Daily)

Chinese tourists watch storm clouds moving along the coast towards the city of Sydney, Australia, November 6, 2015. Powerful storms swept across the city on Friday, with the Australian Bureau of Meteorology issuing a warning for severe thunderstorms with large hailstones, heavy rainfall and damaging winds, local media reported. (Photo by David Gray/Reuters)

Principle Ballet Dancer, Ekaterina Bulgutova, of the Russian State Ballet, with the Nutcracker part of Christmas Ballet Season in Cardiff which starts at St Davids Hall on December 20, 2016 in Cardiff, England. (Photo by Kiran Ridley/Barcroft Images)

A woman doing yoga at a fountain, in downtown Stuttgart, Germany, Thursday, June 22, 2017. Weather forecasts predict hot summer weather as well as thunderstorms for some parts of Germany. (Photo by Marijan Murat/DPA via AP Photo)

Military school cadets take part in a ceremony commemorating the 56th anniversary of the death of Camilo Cienfuegos who, along with Fidel Castro and Che Guevara, was a chief commander of the Cuban revolution in Havana, Cuba on October 28, 2015. (Photo by Xinhua/REX Shutterstock)

Olaf Niess catches swans on the river Alster near the town hall in Hamburg, Germany, 17 November 2015. The Alster swans are moving to their ice-free winter quarters on the Eppendorf Muehlenteich millpond until spring. (Photo by Bodo Marks/EPA)

Migrants rush as they try to get on a train heading to the border with Serbia at the train station of Gevgelija, on the Macedonian-Greek border, on August 9, 2015. Non-EU Serbia's frontier with Hungary, which is in the bloc's passport-free Schengen zone, has become a major crossing point for the huge numbers of migrants entering the EU. (Photo by Dimitar Dilkoff/AFP Photo)