Classic · Nature
Diamond Fuji 2026: dates and times
Tokyo · Lake Tanuki · Lake Yamanaka
Next date Observation deck, 25F · UTC+9
Observation deck, 25F
Sun · at set · Tokyo, Bunkyo Civic Center
From this point the setting sun sits on Kengamine, Mt. Fuji, 100.6 km away: a few hundred metres to one side is enough to miss it.
Next dates
Local times at the site (Asia/Tokyo).
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16:27 UTC+9
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16:56 UTC+9
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16:26 UTC+9
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16:56 UTC+9
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16:26 UTC+9
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16:57 UTC+9
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16:27 UTC+9
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16:56 UTC+9
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16:27 UTC+9
Where to stand
Viewpoint: Observation deck, 25F · Tokyo, Bunkyo Civic Center
35.70810, 139.75240
Lined up with Kengamine, Mt. Fuji, 100.6 km away. Look towards 248° from north.
Good to know
Free observation deck on the 25th floor, closed for renovation since March 2025: Bunkyo City plans to reopen it in early December 2026, so the November 2026 diamond is lost from here. On diamond days it is crowded; check the closing time.
The summit geometry is certain, but the date depends on the exact spot and height you watch from: a few hundred metres moves the day. Cloud on the summit is common.
Tamagawadai Park
Sun · at set · Tokyo, Tamagawadai Park
From this point the setting sun sits on Kengamine, Mt. Fuji, 88.9 km away: a few hundred metres to one side is enough to miss it.
Next dates
Local times at the site (Asia/Tokyo).
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16:41 UTC+9
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17:12 UTC+9
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16:42 UTC+9
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17:11 UTC+9
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16:42 UTC+9
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17:11 UTC+9
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16:41 UTC+9
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17:11 UTC+9
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16:41 UTC+9
Where to stand
Viewpoint: Tamagawadai Park · Tokyo, Tamagawadai Park
35.58500, 139.66800
Lined up with Kengamine, Mt. Fuji, 88.9 km away. Look towards 254° from north.
Good to know
Public park on the Tama river, free.
The summit geometry is certain, but the date depends on the exact spot and height you watch from: a few hundred metres moves the day. Cloud on the summit is common.
Fugaku Terrace
Sun · at rise · Lake Tanuki, Tanukiko Fugaku Terrace
From this point the rising sun sits on Mt. Fuji, west crater rim, 16.0 km away: a few hundred metres to one side is enough to miss it.
Next dates
Local times at the site (Asia/Tokyo).
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06:01 UTC+9
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06:06 UTC+9
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06:00 UTC+9
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06:07 UTC+9
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06:00 UTC+9
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06:06 UTC+9
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06:01 UTC+9
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06:05 UTC+9
Where to stand
Viewpoint: Fugaku Terrace · Lake Tanuki, Tanukiko Fugaku Terrace
35.34178, 138.55411
Lined up with Mt. Fuji, west crater rim, 16 km away. Look towards 82° from north.
Good to know
The deck is public and free, but the lakeside car park is small: arrive before dawn. With a calm lake the diamond is doubled.
The summit geometry is certain, but the date depends on the exact spot and height you watch from: a few hundred metres moves the day. Cloud on the summit is common.
Lake Yamanaka
Sun · at set · Lake Yamanaka, shore
From this point the setting sun sits on Kengamine, Mt. Fuji, 17.1 km away: a few hundred metres to one side is enough to miss it.
Next dates
Local times at the site (Asia/Tokyo).
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16:04 UTC+9
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16:05 UTC+9
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16:05 UTC+9
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16:04 UTC+9
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16:04 UTC+9
Where to stand
Viewpoint: Lake Yamanaka · Lake Yamanaka, shore
35.41980, 138.90100
Lined up with Kengamine, Mt. Fuji, 17.1 km away. Look towards 247° from north. It works across an area around this point, not only from the exact spot.
Good to know
The right spot moves every day: the season runs from mid-October to the end of February, with the east and south shores at either end and, around the solstice, Hana no Miyako Park north of the lake. The date and time here are for Kirara (Hirano). The village runs “Diamond Fuji Weeks” (1–22 February), tripods banned.
The summit geometry is certain, but the date depends on the exact spot and height you watch from: a few hundred metres moves the day. Cloud on the summit is common.
Dates for 2026–2030, worked out by Duskbox’s own astronomy engine: the sun from NREL’s SPA, the moon topocentric, both with atmospheric refraction.
