Twilight
Civil, nautical, and astronomical twilight
Twilight is not one single moment. It is a set of phases based on how far the sun is below the horizon, and each phase feels different outdoors.
By Peter Szucs Last updated: July 14, 2026
Short answer
Civil, nautical, and astronomical twilight are phases of daylight before sunrise or after sunset. Civil twilight happens when the sun is 0 to 6 degrees below the horizon, nautical twilight from 6 to 12 degrees, and astronomical twilight from 12 to 18 degrees.
Twilight phases by sun angle
| Term | Meaning |
|---|---|
| Civil twilight | Sun is 0 to 6 degrees below the horizon. |
| Nautical twilight | Sun is 6 to 12 degrees below the horizon. |
| Astronomical twilight | Sun is 12 to 18 degrees below the horizon. |
| Night | Sun is more than 18 degrees below the horizon. |
Civil twilight
Civil twilight is the brightest twilight phase. The sky still has enough light for many outdoor activities, although artificial light may be needed depending on the place and weather.
For photographers, civil twilight can keep detail in the sky while city lights or window lights begin to show.
Nautical twilight
Nautical twilight is darker. The horizon can still be visible in open areas, but the scene has a stronger evening or pre-dawn feel.
This phase can be useful for seascapes, skyline photos, and routes where you want to understand how quickly light is fading.
Astronomical twilight
Astronomical twilight is the darkest twilight phase before full night. The remaining sunlight is faint, and the sky is closer to true darkness.
It matters for stargazing, night photography, and knowing when sky glow from the sun is mostly gone.
Practical uses
Walking or hiking
Civil twilight is often the most useful planning phase because there is still meaningful ambient light.
Coastal or skyline photography
Nautical twilight can balance a darker sky with visible horizon shape and artificial lights.
Night sky planning
Astronomical twilight helps estimate when the sky is dark enough for stars or low-light work.
Limits
Twilight angle ranges describe the sun position, but clouds, haze, city light, terrain, and latitude can change how bright the sky appears.
Check it in SunCast
Need local twilight times? SunCast shows civil, nautical, and astronomical twilight alongside sunrise, sunset, golden hour, and blue hour.
Frequently asked questions
Which twilight phase is brightest?
Civil twilight is the brightest phase because the sun is closest to the horizon.
When does night begin?
Night begins after astronomical twilight, when the sun is more than 18 degrees below the horizon.
Is blue hour the same as twilight?
Blue hour happens during part of twilight, but it is a photography term rather than one of the formal twilight angle ranges.
