Home / Editor's Pick /

Valentine's phenomenon: Japan's diamond jewellery ice

02:00 PM
February 16, 2025

Winter phenomenon
Japan's diamond jewelery ice

Jewellery ice washed up on Otsu beach in Toyokoro, Hokkaido.Jewellery ice washed up on Otsu beach in Toyokoro, Hokkaido. - © picture alliance

Every winter, Japan's Hokkaido coast is graced by a rare natural phenomenon called "jewelery ice", where the ice sparkles just like diamonds.

The weather is never in short supply of feeling romantic with Japan's jewelery ice. It is created along the country's Hokkaido coast and forms as ice from the Tokachi River breaks apart at the river's mouth and gets washed up on the beach.

Sand and waves together polish the ice to become extremely smooth and shiny. The phenomenon occurs only on Otsu Beach in Hokkaido, during the coldest days of winter, generally between January and February.

During winter, the temperature of the Tokachi River can drop below -4°F, but it can take a long time to freeze. This gives the ice a high transparency with no impurities.

Throughout the day, the angle of the sun bathes the ice rounds in different colors; in an orange glow at first light, to a deep blue later in the day.

Becca Parker
More on the topic
Fog impacting the Appalachian Mountains.
Sunday, October 12, 2025

Low clouds

10 facts about fog
setting-sun
Saturday, September 6, 2025

Coldest time of the day

Lowest temperature is just after sunrise
Dust cloud over Tucson alongside weather radar showing thunderstorms in Arizona.
Sunday, August 31, 2025

Fascinating phenomenon

Dust storm hit Phoenix last week
All weather news
This might also interest you
Wednesday, October 8, 2025

Daily briefing

Autumn air mass settles in, rain for some
Tuesday, October 7, 2025

Daily briefing

Autumn front triggers rainfall, cooldown
Sunday, October 12, 2025

Flood safety

Useful tips when driving in the rain
All articles
Weather & Radar

www.weatherandradar.com

instagramfacebookthreadsContact uslinkList
Privacy policy | Legal info | Accessibility statement