Why Kyoto's cherry blossoms have bloomed unusually early

The arrival of Japan's beautiful cherry blossoms is always a much-anticipated spring attraction, but they have made their appearance the earliest they have in centuries, which some experts think may be due to climate change.

The timing of the appearance of the country’s nationally-revered pink blossoms - known as sakura - depends on the weather conditions leading up to spring. Warmer weather has meant that blossoms in the city of Kyoto peaked on 26 March, which is the earliest date recorded since records began in 812 AD in imperial court documents and diaries. This is collected by Yasuyuki Aono at Osaka Prefecture University.

Cherry blossoms line the Philosopher's Path through the northern part of Kyoto's Higashiyama district in Japan — The country’s nationally-revered pink blossoms are known as sakura © Ark Tui/500px

Each year the Japan Meteorological Corporation , in which it estimates the flowering (kaika) and full bloom dates for Somei Yoshino trees in approximately 1000 viewing locations. The flowering and full bloom dates of cherry blossoms result from the temperature patterns from autumn of the preceding year. The leaves on the cherry blossom trees normally secrete hormones to prevent them flowering ahead of time, but weather conditions can impact this process and make blooming occur earlier.

"The trend over the last 200 years towards earlier flowering in the Kyoto cherry blossoms is due to two things," Benjamin Cook, adjunct associate research scientist at the Earth Institute at Columbia University, tells �ϰ��ϲʿ��¼. "The first is climate change from burning of fossil fuels, which is generally making things warmer pretty much everywhere around the world. The second is an enhanced urban heat island effect associated with increased urbanization in Kyoto, which is also making local temperatures warmer."

As admiring the sakura is a beloved Japanese custom - known as hanami - authorities in Tokyo and neighboring prefectures have become concerned about crowds gathering at popular viewing spots. They have urged residents to be cautious about how they take part in the traditional custom in light of the COVID-19 pandemic.

With travel restrictions still in place in much of the world, seeing the cherry blossoms in Japan might not be possible for most this year. Luckily anyone can watch Washington DC's famous blossoms online with the BloomCam.