ソーラーインサイトプロ — ゴールデンアワー・日の出日の入り計算機

Latitude & Daylight at 東京

東京 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 東京's unique sunrise, sunset, and golden hour patterns year-round.

東京のスカイラインからわずか60km西、奥多摩地域はボートル3〜4の空を提供し、晴れた夜には天の川が肉眼で見えます。世界最大級の都市圏で本物の暗い空にこれほど近いことは極めて稀であり、国立天文台三鷹キャンパスが公開観望会を通じて積極的に推進しています。

Golden Hour Photography at 東京

Golden hour at 東京 occurs when the sun sits between −4° and 6° above the horizon, producing soft, warm, directional light ideal for portrait and landscape photography. At 東京'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.

東京・三鷹にある国立天文台は1878年以来天体を追跡し続けており、アジアで最も歴史のある継続的な天文学機関の一つです。その20cm屈折望遠鏡は1918年に小惑星「東京」を発見し、太陽塔望遠鏡は現在も大都市の中心から日々黒点活動を監視しています。

UV Exposure & Sun Safety at 東京

UV radiation at 東京 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 東京'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 東京

All solar calculations for 東京 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 東京's coordinates (35.7°, 139.7°) — zero server processing means your location data never leaves your device.