Kyoto's cherry blossoms blooming earlier than ever

Yuriko Schumacher | June 10, 2021

Cherry blossoms in the city of Kyoto, Japan peaked on March 26 this year. It was the record-earliest since 812 A.D.

This spring, cherry blossoms saw the peak blooming on March 26 in the city of Kyoto, Japan, according to the Japan Meteorological Agency . This was the record earliest since 812 A.D., according to data released by Yasuyuki Aono, a professor at Osaka Prefecture University. He called it a "concerning trend that could suggest the progression of global warming, if this continues to occur twice or three times in the next 30 years.”

Professor Aono's team identified the full-blooming dates in ancient times "from old documents," such as diaries by emperors and historical documents created by other officials.

The flowering of cherry blossoms has an extremely significant meaning in Japanese spring. Many people like to gather around cherry trees to eat, drink, and take photos. The flowers are also the symbol of graduation and entrance ceremonies, since the Japanese academic year ends in March and starts in April.

In recent decades, the date when the blossoms reach full bloom has been getting earlier and earlier, the data show. “It is a remarkable fact this year’s date broke the record,” Aono pointed out. The previous record was set in 1409, when the full blooming was documented on March 27.

However, Aono said there are numerous factors closely associated with cherry trees’ blooming, including warm weather in early spring and low temperature in winter, both of which the city saw this year. “It is extremely significant to see whether this early blooming trend will continue from now on,” Aono added.

This chart shows cherry blossom's peak dates from 812 to 2021. Cherry blossom petals are placed to represent full-blooming dates, having X-axis for the number of days after Jan. 1, and Y-axis for the year.

Scrolling down will show a zoomed-in version. The gray bar indicates the year that is in view on the zoomed-in version of the chart.

Petal colors represent the year, from 812 to 2021.

Angles of petals indicate the year's average March temperature data (F).

Many studies have shown the temperature in March affects heavily on cherry blossoms blooming. Professor Aono's team estimated average March temperatures from 812 to 1879, based on the cherry blossom's full-blooming date.

From 812 to 1879, the angles represent those estimated temperature data. From 1880 to present, temperature data are actually observed ones, revealed by the Japan Meteorological Agency.

This chart will show the number of observations of peak-blooming dates.

Cherry blossom's full-blooming date in Kyoto

The median date for full blooming between 812 and 2021 is 104 days after Jan. 1.

It was the same between 812 and 1899. But it has been getting earlier.

Between 1900 and 2021, the median date is 98 days.

In 2021, the cherry blossoms in Kyoto set a new early record for peaking, fully blooming 84 days after Jan. 1, on March 26.