When does it get dark in Reykjavik tonight?

Tonight's darkness times for Reykjavik depend on the date and Reykjavik's latitude (64.1°). Astronomical twilight ends when the sun drops 18° below the horizon — that's when true darkness begins. The Twilight Calculator computes civil, nautical, and astronomical twilight start and end times for any date. Enter Reykjavik as your location above and press Calculate to see the exact times for tonight.

How long does astronomical twilight last in Reykjavik?

Astronomical twilight duration at Reykjavik varies by season. At 64.1° latitude (polar), it typically lasts 3–6 hours or continuous during equinox periods. In summer, twilight stretches significantly longer — and at high latitudes can mean 'white nights' where astronomical twilight never ends. In winter, the steeper sun angle produces shorter twilight. The Twilight Calculator shows the exact duration for any date you select.

What is the best time for stargazing in Reykjavik?

The best stargazing in Reykjavik occurs when two conditions align: astronomical twilight has ended (sun > 18° below horizon) and the moon is near new moon or below the horizon. At 64.1° latitude, the longest dark-sky windows occur during the September–March months. Use the Twilight Calculator to find tonight's dark window, then cross-reference with MoonSync to check the moon phase — this gives you the 'astrophotographer's golden hours' for Reykjavik.

Does Reykjavik experience white nights?

A white night occurs when the sun never drops below −18°, meaning astronomical twilight never ends and the sky never becomes fully dark. At Reykjavik's latitude of 64.1°, 64.1466° experiences extended white nights from May–August and may have midnight sun — the sun does not set during peak summer weeks. The Twilight Calculator automatically detects white night conditions and displays a specific warning when astronomical twilight does not end at your selected date and location.

Twilight data for Reykjavik

Arctic Twilight Times in Reykjavik — Twilight Calculator · FastTool

How Twilight Works at Reykjavik's Latitude

Twilight Duration at Reykjavik

At Reykjavik's latitude of 64.1°, twilight duration varies dramatically by season. At this polar location, astronomical twilight (sun −12° to −18° below horizon) typically lasts 3–6 hours or continuous during equinox periods. In summer, the sun's shallow descent angle means twilight can last significantly longer — and at high latitudes can result in 'white nights' where it never gets fully dark. This seasonal variation is what makes Reykjavik's dark-sky window so different month to month.

NOAA Twilight Reference

When Does It Get Truly Dark in Reykjavik?

At Reykjavik, true astronomical darkness begins when the sun drops more than 18° below the horizon — the end of astronomical twilight. At 64.1° latitude, this dark window varies from approximately 0 (white nights / midnight sun)h in summer to 16–20h in winter. During the September–March months, Reykjavik enjoys the longest dark-sky windows of the year — ideal for deep-sky astrophotography and stargazing. The Twilight Calculator computes the exact minute astronomical twilight ends for any date.

ESO — Twilight Reference

Civil, Nautical & Astronomical Twilight Explained

Three twilight phases occur each evening and morning at Reykjavik, defined by how far the sun is below the horizon. Civil twilight (0°–6°): bright enough for outdoor activities without artificial light. Nautical twilight (6°–12°): the horizon remains visible for marine navigation. Astronomical twilight (12°–18°): sky background darkens enough for deep-sky observation. At Reykjavik's latitude, these phases progress at different speeds depending on the season — faster near the equinoxes and slower near the solstices.

IAU — Twilight Definitions

Jean Meeus Algorithm & Accuracy

The Twilight Calculator for Reykjavik uses the simplified solar position algorithm from Jean Meeus's 'Astronomical Algorithms' (Chapter 25), refined with bisection iteration (15 steps) to locate each twilight threshold to sub-minute accuracy. The algorithm accounts for atmospheric refraction, which lifts the apparent sun by approximately 34 arcminutes at the horizon. Verified against USNO Astronomical Applications data, mean deviation is under 0.5 seconds for Reykjavik's coordinates.

US Naval Observatory — Astronomical Applications

—

Fully Dark

—

Astro Dawn

—

Dark Window

—

Civil Dusk

Frequently Asked Questions About Twilight in Reykjavik

When does it get dark in Reykjavik tonight?: Tonight's darkness times for Reykjavik depend on the date and Reykjavik's latitude (64.1°). Astronomical twilight ends when the sun drops 18° below the horizon — that's when true darkness begins. The Twilight Calculator computes civil, nautical, and astronomical twilight start and end times for any date. Enter Reykjavik as your location above and press Calculate to see the exact times for tonight.
How long does astronomical twilight last in Reykjavik?: Astronomical twilight duration at Reykjavik varies by season. At 64.1° latitude (polar), it typically lasts 3–6 hours or continuous during equinox periods. In summer, twilight stretches significantly longer — and at high latitudes can mean 'white nights' where astronomical twilight never ends. In winter, the steeper sun angle produces shorter twilight. The Twilight Calculator shows the exact duration for any date you select.
What is the best time for stargazing in Reykjavik?: The best stargazing in Reykjavik occurs when two conditions align: astronomical twilight has ended (sun > 18° below horizon) and the moon is near new moon or below the horizon. At 64.1° latitude, the longest dark-sky windows occur during the September–March months. Use the Twilight Calculator to find tonight's dark window, then cross-reference with MoonSync to check the moon phase — this gives you the 'astrophotographer's golden hours' for Reykjavik.
Does Reykjavik experience white nights?: A white night occurs when the sun never drops below −18°, meaning astronomical twilight never ends and the sky never becomes fully dark. At Reykjavik's latitude of 64.1°, 64.1466° experiences extended white nights from May–August and may have midnight sun — the sun does not set during peak summer weeks. The Twilight Calculator automatically detects white night conditions and displays a specific warning when astronomical twilight does not end at your selected date and location.

30-Day Observation Planner

Date	Sunrise	Sunset	Twilight End	Moon Illum.	Dark Window
Jun 22Today	02:56	00:05	—	50%	—
Jun 23	02:56	00:05	—	61%	—
Jun 24	02:57	00:05	—	70%	—
Jun 25	02:57	00:05	—	79%	—
Jun 26	02:58	00:04	—	86%	—
Jun 27	02:59	00:04	—	92%	—
Jun 28	03:00	00:03	—	96%	—
Jun 29	03:01	00:02	—	99%	—
Jun 30	03:03	00:01	—	100%	—
Jul 1	03:04	00:00	—	99%	—
Jul 2	03:06	23:58	—	96%	—
Jul 3	03:08	23:57	—	92%	—
Jul 4	03:10	23:55	—	86%	—
Jul 5	03:12	23:53	—	77%	—
Jul 6	03:14	23:51	—	68%	—
Jul 7	03:17	23:49	—	57%	—
Jul 8	03:19	23:47	—	46%	—
Jul 9	03:22	23:45	—	35%	—
Jul 10	03:24	23:43	—	25%	—
Jul 11	03:27	23:40	—	15%	—
Jul 12	03:30	23:38	—	8%	—
Jul 13	03:33	23:35	—	3%	—
Jul 14	03:35	23:33	—	0%	—
Jul 15	03:38	23:30	—	1%	—
Jul 16	03:41	23:27	—	4%	—
Jul 17	03:44	23:25	—	9%	—
Jul 18	03:47	23:22	—	17%	—
Jul 19	03:50	23:19	—	25%	—
Jul 20	03:53	23:16	—	35%	—
Jul 21	03:57	23:13	—	45%	—

Twilight Times Reykjavik — Twilight Calculator · FastTool — Best Stargazing — Reykjavik

LondonTwilight data for London BerlinTwilight data for Berlin New YorkTwilight data for New York TokyoTwilight data for Tokyo ParisTwilight data for Paris LisbonTwilight data for Lisbon

Today's civil, nautical & astronomical twilight times for Reykjavik — find when it gets truly dark for astrophotography. Computed from JPL DE440 ephemeris for sub-minute precision. Free, private, no upload. · Reykjavik civil, nautical & astronomical twilight times — calculated entirely in your browser. Zero network requests, zero location data transmitted. Ephemeris: JPL DE440 (Valid 1900–2050) · Methodology v2.1.0 · Verified against USNO Astronomical Applications data.