Home / Editor's Pick /

Valentine's phenomenon: Japan's diamond jewellery ice

10:00
14 February 2025

Valentine's phenomenon
Japan's diamond jewellery 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 "jewellery ice", where the ice sparkles just like diamonds.

The weather is never in short supply of feeling romantic with Japan's jewellery 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 -20°C, 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 colours; in an orange glow at first light, to a deep blue later in the day.

Ski trip? Ski & Mountain weather in appread more
Ryan Hathaway
More on the topic
Monday 30 June 2025

Noctilucent cloud season

Shimmering clouds over UK and Ireland
summer solstice
Saturday 21 June 2025

Summer solstice

Longest day of the year is here
Friday 20 June 2025

Storms after the heat

Thunderstorm warnings for the weekend
All weather news
This might also interest you
Wednesday 2 July 2025

Isolated strikes here

Storms across Europe mostly miss UK
Thursday 3 July 2025

Breakfast brief

Pleasant for some, unsettled for others
Thursday 3 July 2025

Gusty too

Rainfall passes through the north
All articles
Weather & Radar

www.weatherandradar.ie

facebooktwitteryouTubeContact uslinkList
Privacy Policy | Legal info | Accessibility statement