What Time Is Nautical Twilight Today?
Today's nautical twilight windows for your location are shown above with a live countdown to the next one. It comes twice a day — the morning stage runs up to civil twilight before sunrise, and the evening stage picks up after civil twilight and runs down into night. On the animated sun path, the deep-blue band on each side marks where nautical twilight falls today.
What Is Nautical Twilight?
Nautical twilight is the middle of the three twilight stages, defined by the sun sitting between 6° and 12° below the horizon. To the eye it already looks like night: the sky is dark, the brighter stars and planets are out, and colors are gone. What still lingers is a faint band of light along the horizon — and at sea that's the whole point. For centuries it was the only time a navigator could see both the star being measured and the sea horizon beneath it, the two references a sextant needs. That's how the stage earned its name.
Nautical Twilight vs Civil and Astronomical Twilight
The three stages are graded by how far the sun has sunk:
- Civil twilight (0° to −6°) — bright enough to walk, read, and work outdoors.
- Nautical twilight (−6° to −12°) — this page. Dark on the ground, horizon still visible at sea.
- Astronomical twilight (−12° to −18°) — looks fully dark; only telescopes notice the last glow. Past −18° is true night.
FAQ
When does nautical twilight end tonight?
Evening nautical twilight ends when the sun drops 12° below the horizon, at which point astronomical twilight begins — tonight's exact time is in the cards above, with a live countdown.
Is nautical twilight the same as nautical dawn and dusk?
Morning nautical twilight is also called nautical dawn; the evening stage is nautical dusk. Same windows, named for the time of day.
How is nautical twilight calculated?
From the sun's elevation, computed for your location using only your timezone — no location permission needed. Tap "Use precise location" for street-level accuracy.
