Latitude & Daylight at Tokyo

Tokyo sits at latitude 35.7°. At this latitude, daylight varies from approximately 14.4h in summer (solstice) to 14.4h in winter — a seasonal swing of 0.0h. The sun reaches a maximum altitude of 77.8° at summer solstice and a minimum of 30.9° at winter solstice. This mid-latitude profile is what shapes Tokyo's unique sunrise, sunset, and golden hour patterns year-round.

Just 60 km west of Tokyo's skyline, the Okutama region offers Bortle 3-4 skies where the Milky Way is visible to the naked eye on clear nights. This proximity to genuine dark skies in one of the world's largest metropolitan areas is vanishingly rare — actively promoted by NAOJ's Mitaka Campus through public stargazing programs.

Golden Hour Photography at Tokyo

Golden hour at Tokyo occurs when the sun sits between −4° and 6° above the horizon, producing soft, warm, directional light ideal for portrait and landscape photography. At Tokyo's latitude, morning golden hour typically starts in the hour after sunrise and lasts approximately 28–40 minutes. Evening golden hour mirrors this before sunset. The longer twilight at this latitude gives photographers more time to capture the 'magic hour' compared to equatorial locations where the sun sets more steeply.

The National Astronomical Observatory of Japan in Mitaka, Tokyo, has been tracking celestial objects since 1878, making it one of Asia's oldest continuous astronomical institutions. Its 20-cm refractor discovered the asteroid 'Tokyo' in 1918, and its solar tower telescope still monitors sunspot activity daily from the heart of the metropolis.

UV Exposure & Sun Safety at Tokyo

UV radiation at Tokyo peaks when the sun is highest in the sky — around solar noon. At 35.7° latitude, peak UV levels vary significantly by season: summer months see UV indices of 6–9 (high), while winter months typically register 1–3 (low). The World Health Organization recommends sun protection when UV index exceeds 3. At Tokyo's latitude, this threshold is exceeded for approximately 6–8 months per year, making sun awareness a year-round consideration for outdoor workers and athletes.

How We Calculate Solar Data for Tokyo

All solar calculations for Tokyo use the Jean Meeus Chapter 25 solar position algorithm with bisection iteration, accurate to ±1 minute for dates between 1901–2099. Sunrise and sunset times define the moment the upper limb of the sun appears on the horizon, accounting for atmospheric refraction. Daily data is calculated client-side from Tokyo's coordinates (35.7°, 139.7°) — zero server processing means your location data never leaves your device.