A hot air ball balloon floats past while people stand in line to climb the Pyramid of the Sun and welcome the spring equinox in the pre-hispanic city of Teotihuacan, on the outskirts of Mexico City, Mexico, March 20, 2016. Spring equinox in Teotihuacán is an annual event which takes place around the 20th and 21st of March at the pre-Hispanic site of Teotihuacán, Mexico. This event is mirrored by other similar events in other pre-Hispanic sites such as Chichén Itzá and Malinalco, Mexico State. (Photo by Edgard Garrido/Reuters)

Cassandra Cantu shields her 7-week-old puppy Kamala from the snow as she walks with friends in the Bear Creek Dog Park in Colorado Springs, Colo., Sunday, May 11, 2014. A spring storm that has brought over a foot of snow to parts of Colorado, Wyoming and Nebraska and thunderstorms and tornadoes to the Midwest was slowing down travelers and left some without power Monday morning. (Photo by Mark Reis/AP Photo/The Gazette)

Japanese Macaque monkeys soak in the warmth of mountain hotsprings at Jigokudani Monkey Park, in Yamanouchi, central Japan, 19 January 2014. The Japanese Macaques (Macaca fuscata), also referred to as Snow Monkeys, live freely in this area that is covered by snow one third of the year. Jigokudani is the only known place in the world where monkeys bathe in natural hot springs. As a habit, they come down from the mountains where they spend the night and bath during the day. (Photo by Kimimasa Mayama/EPA)

The North Side Skull & Bone Gang stand together during the wake up call for Mardi Gras, Tuesday, February 9, 2016, in New Orleans. Their costumes are intended to represent the dead and they bring a serious message, reminding people of their mortality and the need to live a productive and good life. (Photo by Brynn Anderson/AP Photo)

Members of the samba school of the Grupo Especial Independencia Tricolor participate in the carnival celebration at the Anhembi sambodrome in Sao Paulo, Brazil, 09 February 2018. (Photo by Sebastiao Moreira/EPA/EFE)

A man holds his umbrella during snowfall on the Areopagitou pedestrian street beneath the Acropolis hill during snowfall in Athens, Greece, January 10, 2017. (Photo by Alkis Konstantinidis/Reuters)

Visitors look at a tower exhibit of 429 different kinds of pumpkins and squash from all over the world at the Buschmann and Winkelmann pumpkin farm on October 9, 2011 in Beelitz, Germany. The farm, located in Brandenburg state near Berlin, harvests tens of thousands of pumpkins from approximately 40 different kinds between August and October and is known for its elaborate, theme-based pumpkin exhibits. (Photo by Sean Gallup/Getty Images)