Japanese cherry blossoms happen earlier (linear fit)

Data shows that since the 9th century, the date of the full flowering of Kyoto’s cherry trees happens about 4 days earlier every 70 years.

Article from the BBC: “The cherry blossom season, Japan’s traditional sign of spring, has peaked at the earliest date since records began 1,200 years ago, research shows.” March 2020

• PPT slides from Deborah Hughes-Hallett for teachers with details about this activity.

• Spreadsheet with data and plots.

• The original source for the data is no longer available. It was obtained from http://atmenv.envi.osakafu-u.ac.jp/aono/kyophenotemp4/, Date accessed: September 13, 2025.

• Alternate source for the data:

  Aono, Y.; Saito, S.; Kazui, K. (2019-03-23): NOAA/WDS Paleoclimatology - Kyoto, Japan 1,200 Year Cherry Tree Flowering Dates and March Temperature Reconstructions. NOAA National Centers for Environmental Information. https://doi.org/10.25921/1xy4-ht08. Accessed June 2026.

See also:

• Our world in data shows a 20 year average that indicates a strong recent drop.