Tokyo expected to be mainland Japan's earliest bloomer in sakura season

Warmer temperatures, heat island effect’ impacting when cherry blossoms flower

- Walter Sim

Tokyo is poised to buck historical trends and become the first area on mainland Japan where the famous sakura (cherry blossoms) flower and enter full bloom.

In fact, the ephemeral flower, which lasts about two weeks and heralds the dawn of spring, is blooming earlier than before across the country due to global warming.

The Japan Weather Association (JWA) predicts that for 2024, the sakura will flower in Tokyo on March 19 and reach full bloom on March 25 – both dates the earliest across Japan.

Another prediction, by the Japan Meteorological Corporation (JMC), has the sakura flowering in Tokyo on March 23. Full bloom is forecast on March 30, earlier than in areas such as Kyoto and Osaka.

Tokyo is suffering the double whammy of warmer temperatures and the “heat island effect”, Japan Meteorological Agency (JMA) climate risk management officer Daisuke Sasano said on March 12. The heat island effect refers to how urban areas are warmer than rural regions as heat is absorbed and reflected by man-made structures.

JMA records show that mean temperatures across Japan have risen 1.6 deg C in the last century, with 2023 the hottest year on record. In Tokyo, however, the mercury has spiked an average 3.3 deg C over 100 years.

All 47 prefectures have at least one “specimen tree”. When five to six flowers on the specimen tree open, the sakura in an entire region is said to have started flowering. Full bloom happens when 80 per cent of the buds of the tree have opened.