Swiss police officers stand beside of mock gates of the NEAT Gotthard Base Tunnel inside the event hall for the upcoming opening ceremony near the town of Erstfeld, Switzerland May 31, 2016. The celebrations of the opening of the Gotthard Base Tunnel will start on June 1, 2016. With a length of 57 km (35 miles) crossing the Alps, the Gotthard Base tunnel is the world's longest train tunnel. (Photo by Arnd Wiegmann/Reuters)

People walk under Australia's iconic landmark Harbour Bridge in Sydney on April 3, 2019, as heavy fog blankets the city. Low visibility due to heavy fog affected traffic in the city and caused flight delays at the Sydney airport. (Photo by Saeed Khan/AFP Photo)

People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)

A reveller performs while attending the block party “Galo da Madrugada” during carnival festivities in Sao Paulo, Brazil on February 25, 2020. (Photo by Rahel Patrasso/Reuters)

Revellers brave the rain as they make the most of New Year's Eve in Liverpool city centre, UK on December 31, 2024. (Photo by Ioannis Alexopoulos/London News Pictures)

Goodwood racegoers run for cover from a sudden rainstorm on Ladies Day, the third day of the horseracing festival at Goodwood Racecourse on July 31, 2025 in Chichester, England. (Photo by The Times)

Revellers battled against 40mph winds and driving rain to get to nightclubs in Birmingham city centre on September 21, 2025. The Met Office released a yellow weather warning for strong wind and heavy rain overnight across much of England and Wales. The partygoers used their coats and umbrellas to shelter from the barmy conditions. (Photo by British News and Media/Alamy Live News)

Afghan air force 2nd Lt. Niloofar Rhmani walks the flight line at Shindand Air Base, Afghanistan, prior to her graduation from undergraduate pilot training, on May 13, 2013. Rhmani made history on May 14, when she became the first female to successfully complete undergraduate pilot training and earn the status of pilot in more than 30 years. She will continue her service as she joins the Kabul Air Wing as a Cessna 208 pilot. (Photo by Senior Airman Scott Saldukas/USAF)