Japan’s ‘Snow Monsters’: The frozen giants of Zao that only appear for weeks and locals say they are slowly disappearing (Image source: Canva)
In the depths of winter, the forests of the Zao Mountain Range transform into something almost surreal. Trees no longer look like trees. They rise in huge, twisted shapes, covered in layers of thick white ice, and stand silently against the wind.
Visitors call them “snow monsters” in Japan. In Japanese, they are known as gohyo, literally meaning “ice trees.”At first glance, it seems legendary. In fact, they are the result of a delicate and fragile atmospheric process. Scientists warn that the conditions necessary to create them are becoming more difficult to maintain.
The science behind Japan’s snow monsters
These formations occur primarily on Mount Jizo in Zao, which runs between Miyagi and Yamagata Prefectures. According to researchers at Yamagata University. juhyo They form when strong monsoon winds blow in from the Sea of Japan, carrying clouds filled with supercooled water droplets.
When these drops hit pine trees, especially the native Aomori tree, they freeze instantly.Over days and weeks, layers of ice accumulate. The ice thickens on the leeward side of the tree, gradually forming ridges known locally as “shrimp tails.” As more ice accumulates, the trees lose their natural shape and take on massive shapes that earn them the nickname “snow monsters.”According to local tourism authorities and Zao Ropeway, the best time to see this phenomenon is usually from mid-January to early March, when temperatures stay consistently below freezing, and winds are strong enough to keep ice forming.
From Hokkaido to Ishikawa: The Lost Range of Japan’s Snow Monsters
What many visitors don’t realize is that these snow monsters were once widespread.Professor Fumitaka Yanagisawa, professor emeritus at the Zao Ice Monsters and Volcanoes Research Institute at Yamagata University, has spent years examining historical photographs and mountaineering records. According to his research, the Gohyo formations have been documented not only in Zao but also throughout Hokkaido and as far south as Ishikawa Prefecture. Historical records indicate that it extended up to 50 to 60 kilometers from the Sea of Japan until about the middle of the 20th century.One of the oldest confirmed photos dates back to 1921, and was taken by the Mountaineering Club of Keio University in Zao. Another rare photograph from 1923 has been identified in Toyama Prefecture. Additional documents from Nagano and Niigata prefectures support the idea that the gohyo once covered a wider geographic range.Today, the most important remaining sites are all located in three places: Mount Zao, Mount Hakoda, and Mount Moriyoshi.
Among them, Zhao is still the largest and most famous.
What do rising temperatures mean for snow monsters in Japan?
The reason for their decline is not folklore but physics.According to climate analysis conducted by Professor Yanagisawa, rising winter temperatures and slight shifts in wind patterns reduce the frequency of ideal conditions for johyo formation. Even small increases in average winter temperature can make freeze-up periods shorter, reduce the amount of frigid cloud water, and harm the health of the Aomori fir forests that support the formations.According to the Japan Meteorological Agency, data over recent decades show a gradual warming trend in winter temperatures in northern Japan. While researchers have stopped short of predicting a complete disappearance, projections indicate that without significant climate stabilization, the density and extent of juhyo may continue to shrink by the end of the century.In this sense, the Snow Monsters are more than just a tourist attraction.
They are clear signs of environmental change.
The cultural attraction of the frozen giants
The emotional connection is deeper than science. People living in Yamagata and Miyagi remember the snow monsters from their childhood, the winter festivals, and the nighttime rides along the ropeway.Their ghostly forms are naturally reminiscent of Japan’s long history of folk tales. Shintoists believe that kami, or spirits, inhabit nature. The strange shapes that appear in winter often remind visitors of yōkai, supernatural beings from Japanese stories.
The Snow Woman, Yuki Onna, is one of these characters. Its story goes back to the Muromachi period.The fact that Gohyo resembles these legends adds to its mystery, even though it does not come directly from them. In books such as Ancient Tales and Japanese Folklore, British naturalist Richard Gordon-Smith and other early Western observers wrote about winter folklore, saying that snow spirits haunted mountain landscapes.
The images still have an impact today.
Right now, the Snow Monsters in Zao still rise every winter
Every year, thousands of people go to Zao to see the glowing ice formations in the night sky. Skaters move between the frozen towers, and photographers take pictures of strange shapes.But scientists are still monitoring the forests closely. The main goals are to study weather, monitor forest health, and learn how long-term warming could change mountain ecosystems in northern Japan.The snow monsters are still around right now. When the winds are cold enough and the clouds are heavy enough, they rise again each winter.But their future depends on the fragile balance of time, temperature and wind. In Zaw, many realize that equations like these are becoming more difficult to balance.
