The peak flowering of cherry trees in Kyoto, Japan, has been recorded since the ninth century. Yasuyuki Aono and colleagues from the Osaka Prefecture University collated this data from historical diaries and chronicles, indicating the dates on which cherry blossom viewing parties had been held or other observations of peak blossom.
In 2023, the peak cherry blossom happened on 25 March — the earliest date since recording began.
This long-run data is a proxy measure for how the climate has changed. The onset of the cherry blossom is linked with warmer temperatures. The combined effects of urbanization and higher temperatures due to climate change have caused the peak blossom to gradually move earlier in the year since the early 20th century.
