Sakura AI: Japan’s cherry blossom forecasting competition 2019

It is impossible to think of springtime in Japan without an iconic image of a sea of cherry trees with perfect pink blooms instantly coming to mind. Leading the way in robotics and skyscraper technology, the Japanese have long been celebrating the cherry blossoms known as sakura.


They have been an inspiration for painters, poets and philosophers. And they are even sprinkled on Starbucks lattes. Many tourists plan their entire trips around the blooms, and Japanese flock to parks in droves to enjoy the seasonal spectacle.

“People pay more attention to the cherry blossom season than any other flower in Japan”

Ryo Dojo / Statistics unit at the Meteorological Agency

When do the cherry trees bloom in Japan?

The country’s weather forecasters face one of their biggest missions of the year: predicting exactly when the famed cherry blossoms will bloom.

The most important factor in determining the sakura dates is the geographical location – the milder the climate, the earlier the blossoms open. The dates also differs from year to year depending on the weather. From year to year, the start of the cherry blooming season generally varies by plus/minus one week.

Humans vs AI competition: predicting the cherry blossom dates

Who can more accurately predict when Japan’s cherry trees will bloom, artificial intelligence or humans? Shimadzu Business Systems Corp., a Kyoto-based subsidiary of Shimadzu Corp., started a unique competition.

The results of the competition will be announced on April 5 on the company’s Otenki Japan weather forecast website.

Sakura Tokyo 2018. Video:

In the company, human weather forecasters had predicted the blooming dates until 2017, but in 2018 the AI replaced them for the first time. However, the hit ratio of the AI predictions was lower than the ratio for predictions by Hisashi Kataoka. He has worked as a weather forecaster for 17 years.


Cherry blossom blooming forecast (date of first bloom) – 2019

It will be blooming earlier than normal year nationwide. In eastern Japan to northern Japan, there are places where flowering blooms as early as about a week from the normal year.

See the predictions from the competition organizers’ website:

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