Japan in Seasons

Bloom front

Watch the bloom move north. Drag the date.

Region Open the map

Loading forecast data…

Drag with Shift or right-click to rotate. Q and E turn, W and S tilt.

Vertical exaggeration

Loading

Playback speed

Cities in bloom

Front speed km per day northward

Year by year

Dates. City dates come from the Japan Meteorological Agency (JMA) observation trees once recorded, otherwise from the Japan Meteorological Corporation (JMC) forecast. Spot dates are JMC forecasts. Averages are the normal dates published with the forecast. For autumn leaves, JMC gives only the difference from normal.

Okinawa, Amami and five Hokkaido cities are not in the JMC forecast. Their dates are this year's JMA observations. Okinawa and Amami watch the Taiwan cherry, which blooms in winter; most of Hokkaido watches the Sargent cherry.

Maple and ginkgo. JMC forecasts both per city, and they turn at different times. Most forecast spots are maple; the ginkgo colour at maple and mixed spots is estimated by shifting each spot's maple dates by the nearby cities' ginkgo-to-maple gap. Ginkgo trees stand only at ginkgo and mixed spots. Three cities have no ginkgo forecast.

Autumn colour and height. Leaves turn on the ridges first and the colour works down the valleys. The autumn wash adds a height term: each spot and city is reduced to a sea-level date and the map's own height is added back, at a rate fitted from mountain spots against the cities around them (about 2.5 days per 100 m, kept within the 1 to 4 days that JMA describes). Heights come from the same terrain tiles, about 2 km apart, so this is an estimate between spots.

Snow on high peaks is a seasonal tint by month, not an observation: white above about 2,000 m from December to February, rising to about 2,800 m in May, none from June to September.

Shading. Colour between spots is estimated from the six nearest spots and cities. It fades out 28 km from the nearest one, so open sea and empty mountains stay plain. Each group of trees stands on a real forecast spot.

Front speed is how fast the estimated arrival line moves, averaged over a week.

Year by year. JMA phenological observation tables, 1953 onward (Government of Japan Standard Terms of Use). Hollow dots are years JMA watched a stand-in species. Autumn history uses JMA maple colouring (kaede) or ginkgo yellowing (icho). The dashed line is a straight-line fit; the solid line is a 10-year running mean. This year's forecast, when not yet observed, is a hollow ring.

Kyoto since 812. Full bloom of mountain cherry from court diaries and records: Aono and Kazui (2008), Aono and Saito (2010), Aono (2012) and Katata (2026), via Our World in Data, CC BY 4.0. The line is the 30-year average.

Terrain. Terrain Tiles on AWS (Mapzen, sources). Map drawn with MapLibre GL JS.

Overview

At cursor hover the map

Point at a city, a tree or any place on the map.

All cities

© 2026 Haoming Koo · Privacy · Terms · Contact ([email protected]) · More projects → kooexperience.com