Balancing tradition and animal welfare: Adapting an animal-involving festival to climate change in Fukushima, Japan.

Climate change poses critical risks to humans and animals, particularly during outdoor events. The Soma Nomaoi Festival in Fukushima, Japan, with a thousand-year history involving horses and riders, has become vulnerable to rising summer temperatures. In 2023, during a record high of 35.2 °C, 83 heatstroke cases occurred, including 74 among spectators and nine among horse riders, with two horse fatalities and 111 horses requiring medical care. In response, organizers rescheduled the 2024 festival to May, resulting in a maximum temperature of 24 °C. Human heatstroke cases dropped by 83 % (to 18 cases), and equine cases fell from 111 to 38. Although injuries from heightened horse activity increased, overall welfare improved. This case illustrates how traditional festivals can adapt to climate change while preserving cultural integrity. The experience demonstrates the value of the One Health approach in balancing cultural tradition, human safety, and animal welfare.