Twelve centuries of cherry blossoms — peak bloom in Kyoto, 812–2026

Kyoto · 京都

The peak bloom date of Kyoto’s cherry trees has been written down for more than a thousand years. Stitched together, the entries form what is widely considered the longest continuous record of any natural phenomenon on Earth.

How to read it

Each pale dot is a single recorded peak: the day a designated tree in Kyoto was judged to be at full bloom that spring. The earliest entry is from 812. There are gaps — some centuries are sparse — but the record runs continuously enough that a 30-year rolling mean (the rose line) traces a coherent climate signal over the full span.

For most of the past millennium the line wandered between early and mid April. The Little Ice Age shows up as the slow drift toward later peaks from roughly the 14th to the 19th centuries. Then, starting around 1900, the line begins falling. By the late twentieth century the rolling mean has crossed below any value seen since the Heian court was making the entries by hand.

The 2026 peak fell on March 29 — more than two weeks earlier than the pre-modern average. The signal is local to one species in one city, but it is uniquely well-documented, and uniquely long.

Source & method

Phenological observations compiled by Yasuyuki Aono (Osaka Prefecture University) from imperial diaries, monastery records, and modern meteorological data, archived at NOAA Paleoclimatology. The 30-year rolling mean is computed where at least five observations fall inside the window. Data accessed via Our World in Data (CC‑BY).

Download the data (CSV, 838 rows).

Words for the bloom

Recording the bloom for a thousand years gave Japanese a precise vocabulary for it. Each stage of the cherry tree’s spring has its own word — taught to schoolchildren and read on the weather forecast every March.

• 桜sakuracherry blossom — both the tree and the flower
• 開花kaikaopening — the day the first buds break
• 満開mankaifull bloom — the brief week everyone waits for
• 花吹雪hanafubukiblossom blizzard — the storm that ends the season

JIVX is a Japanese practice app: short, AI-graded sessions in the words and grammar Japan actually uses. The cherry-blossom set has audio, example sentences, and grammar notes for the words above and a few dozen more.

Practice the rest at JIVX →