What is the moon phase tonight in Reykjavik?

Tonight's moon phase for Reykjavik is displayed in real time on MoonSync. The page loads with Reykjavik's coordinates (64.1°, -21.9°) and shows the current moon illumination percentage, lunar age (days since new moon), moonrise and moonset times, and the moon's position above Reykjavik's horizon. All calculations run client-side — no location data is sent anywhere.

When is the next full moon visible from Reykjavik?

MoonSync's lunar calendar shows the full moon phase progression for any date and location, including Reykjavik. Full moons occur approximately every 29.53 days. At 64.1° latitude, full moons near the winter solstice rise at their highest point in Reykjavik's sky, while full moons near the summer solstice stay lower on the horizon — this seasonal variation is why winter full moons appear more dramatic from Reykjavik.

How does the moon's phase affect stargazing in Reykjavik?

Moon phase is the single most important factor for stargazing quality at Reykjavik. A full moon (100% illumination) brightens the sky enough to obscure all but the brightest stars and makes deep-sky observation nearly impossible. For the best stargazing in Reykjavik, plan sessions during the 7 days around New Moon when illumination is below 15%. Use MoonSync to find the next New Moon date, then use the Twilight Calculator to check when astronomical darkness begins.

Why does moonrise time change each day in Reykjavik?

The moon rises approximately 50 minutes later each day as seen from Reykjavik because the moon orbits Earth at about 1 km/s, moving approximately 13° eastward per day against the background stars. Since Earth rotates 360° in 24 hours (15°/hour), the extra 13° of rotation takes roughly 50 minutes. This daily delay explains why the moon is sometimes visible in Reykjavik's daytime sky and why moonrise can occur at any hour of the day or night.

Moon data for Reykjavik

Polar Moon Phases in Reykjavik — MoonSync · FastTool

How Moon Phases Work at Reykjavik's Latitude

Moon Phases Visible from Reykjavik

From Reykjavik at latitude 64.1°, the moon's appearance follows the same 29.53-day synodic cycle visible worldwide — all 8 phases from New Moon through Full Moon and back. However, Reykjavik's polar latitude affects the moon's maximum altitude in the sky. The moon can reach up to 54.5° altitude when crossing the meridian near summer solstice, and only -2.7° near winter solstice. This seasonal variation determines how high the moon appears above Reykjavik's horizon and affects lunar photography planning.

NASA Moon Phase Reference

Moonrise & Moonset Times at Reykjavik

The moon rises approximately 50 minutes later each day as seen from Reykjavik. This daily delay occurs because the moon orbits Earth eastward at about 1 km/s, moving roughly 13° per day against the background stars. At Reykjavik's latitude (64.1°), the moon's rise and set positions along the horizon shift seasonally — rising further north in summer and further south in winter. MoonSync calculates exact moonrise and moonset times for Reykjavik using real-time ephemeris data.

USNO Moonrise Data

Moon Illumination & Reykjavik's Dark-Sky Planning

For stargazing and astrophotography in Reykjavik, moon illumination percentage is the critical number. A Full Moon (100% illuminated) washes out all but the brightest stars and makes deep-sky observation nearly impossible. The 7 days around New Moon (0-15% illumination) provide the best dark-sky window. At 64.1° latitude, combine moon phase with the Twilight Calculator to find nights when both astronomical darkness and minimal moonlight coincide — these 'astrophotographer's golden hours' occur roughly once per month at Reykjavik.

IAU — Observing Conditions

Lunar Data Accuracy for Reykjavik

MoonSync computes moon phase, illumination, moonrise/moonset times, and lunar age for Reykjavik using real-time ephemeris data. Phase illumination is accurate to ±1%. Moonrise and moonset times are calculated from Reykjavik's precise coordinates (64.1°, -21.9°) and corrected for atmospheric refraction. The Keplerian orbital model used achieves timing accuracy of approximately ±30 minutes over a synodic month. For sub-minute lunar event timing, consult the USNO Phases of the Moon data service.

USNO Phases of the Moon

56%

Illumination

14:39

Moonrise

01:14

Moonset

Good

Photo Window

MoonSync

MoonSync — Lunar Clock & Site Selector

Lunar Coordinated Time, selenographic site selector & Moon resident pass

Showing example data: Apollo 11 — Tranquility Base. Click the map or choose a preset to view your site.

Lunar Time (LTC)

Moon Coordinated Time

2026-06-22 12:32:49.284 LTC

Earth UTC

2026-06-22 12:32:48.743 UTC

Accumulated drift since page load

+0.000000 μs ahead of Earth

Lunar Calendar

Moon PhaseWaxing Crescent

Days since new moon7.11 / 29.53

Cycle Progress24.1%

🌑 New🌕 Full🌑 New

Lunar Site Map

Lat: +0.7° Lon: +23.5°

Click anywhere on the map to select a lunar site

Preset Sites

Moon Illumination

56.0%

Phase: Waxing Crescent

LIVE

Observer Location

Lat

Lng

Moonrise

02:39 pm

Moonset

01:14 am

Moon is below the horizon

Illumination Status

Lighting State

Lunar Night

Until next sunrise

2d 5h

Solar Position

Altitude

-26.8°

Azimuth

Below horizon

Earth–Moon Distance

3,73,072kmLIVE

Earth Phase (from Moon)

Earth illumination

52.9%

Earth's illuminated fraction as seen from this lunar site.

Phase

Last Quarter Earth

Environmental Insights

Surface Temperature Estimate

-173.1°C

Based on Stefan-Boltzmann solar angle model. Range: −173°C to +127°C.

Solar Panel Output

Panel area (m²):

0 W

Solar constant: 1,361 W/m²

Shadow Length (1 m object)

No shadow — nightside

Moon Resident Pass

Coordinates

0.67°N, 23.47°E

LTC Timestamp

2026-06-22 12:32:49.284 LTC

Lighting

🌑 Lunar Night

Surface Temp.

-173.1°C

Badge

⚑ Lunar Archaeologist

Issued by MoonSync · fastool.io

Badge

Lunar Archaeologist

Solar Position & Twilight Calculator — Solar InsightCalculate solar altitude, azimuth, golden hour, and civil/nautical/astronomical twilight for any location on Earth.fastool.io Sidereal Time Calculator for AstronomersConvert between local sidereal time and UTC for telescope alignment and observation planning.fastool.io

How MoonSync Works

What Is Lunar Coordinated Time (LTC)?

LTC is a proposed Moon-based time standard. NASA's 2023 analysis found that Moon clocks gain +56.02 µs per Earth day: weaker lunar gravity causes a gravitational blueshift that outweighs the transverse Doppler redshift from lower orbital velocity. MoonSync accumulates this offset from J2000.0 (Jan 1, 2000 12:00 UTC).

NASA — What Time Is It on the Moon?

How Is Moon Illumination Percentage Calculated?

Moon illumination from Earth is the fraction of the Moon's visible disk lit by the Sun. At New Moon (0%), the Moon is between Earth and Sun, showing only its dark side. At Full Moon (100%), Earth is between Moon and Sun. The percentage follows a smooth sinusoidal curve over the 29.53-day synodic month. MoonSync calculates this in real-time using solar and lunar ephemeris data.

USNO — Moon Illumination Data

What Is a Permanent Shadow Region (PSR)?

PSRs are craters near the lunar poles never exposed to direct sunlight, due to the Moon's low axial tilt (1.54°). Temperatures hover around −230 °C, cold enough to trap water ice for billions of years. NASA's LCROSS mission (2009) confirmed water ice deposits in Cabeus crater near the south pole, making PSRs prime candidates for future lunar bases.

NASA Science — Permanently Shadowed Craters

How Is Earth–Moon Distance Calculated?

MoonSync uses a first-order Keplerian ellipse: r = a(1 − e·cos M), where a = 384,399 km (semi-major axis), e = 0.0549 (eccentricity), and M is the mean anomaly from perigee. Accuracy is ±3,000 km. For navigation-grade ephemerides, NASA/JPL's Horizons system integrates the full DE440 planetary solution.

JPL Horizons — Lunar Ephemeris

Frequently Asked Questions

What is Lunar Coordinated Time (LTC)?: LTC is a proposed Moon-based time standard. Because lunar gravity is weaker (gravitational blueshift) and the Moon's orbital speed is lower (transverse Doppler redshift), Moon clocks run approximately +56.02 µs faster per Earth day than Earth clocks. MoonSync cumulates this offset from J2000.0 (Jan 1, 2000, 12:00 UTC) to display the total LTC lead over UTC at any moment.
Why is the lunar surface temperature so extreme?: The Moon has no atmosphere to distribute or retain heat. In direct sunlight, temperatures reach +127 °C (400 K) at the sub-solar point; on the nightside they fall to −173 °C (100 K) — a 300 °C swing driven purely by the presence or absence of solar radiation. MoonSync estimates temperature using the Stefan–Boltzmann model: T (K) = 400 · sin(altitude)^0.25.
What is a Permanent Shadow Region (PSR)?: PSRs are polar craters on the Moon that have never received direct sunlight, due to the Moon's low axial tilt (1.54°). Temperatures can fall to −230 °C — cold enough to preserve water ice for billions of years. NASA's LCROSS mission (2009) confirmed water ice at the lunar south pole. MoonSync classifies any polar site (|lat| ≥ 87°) with negative solar altitude as a PSR.
How accurate are MoonSync's calculations?: MoonSync uses simplified Keplerian orbital elements and geometric optics suitable for education and illustration — not for navigation. Earth–Moon distance accuracy is ±3,000 km; LTC offset uses NASA's 2023 value of +56.0205 µs/day; phase timing drifts ≈±30 min over a synodic month. For navigation-grade results, consult JPL Horizons or USNO data.
When will the moon rise and set at my location?: MoonSync calculates moonrise and moonset times using your browser's location (or manually entered coordinates). The Moon rises roughly 50 minutes later each day due to its eastward orbital motion. Moonrise/moonset times depend on your latitude, the Moon's declination, and the current lunar phase. MoonSync uses real-time ephemeris data to compute accurate rise/set times and shows whether the Moon is currently above or below your horizon.

Frequently Asked Questions About Moon Data in Reykjavik

What is the moon phase tonight in Reykjavik?: Tonight's moon phase for Reykjavik is displayed in real time on MoonSync. The page loads with Reykjavik's coordinates (64.1°, -21.9°) and shows the current moon illumination percentage, lunar age (days since new moon), moonrise and moonset times, and the moon's position above Reykjavik's horizon. All calculations run client-side — no location data is sent anywhere.
When is the next full moon visible from Reykjavik?: MoonSync's lunar calendar shows the full moon phase progression for any date and location, including Reykjavik. Full moons occur approximately every 29.53 days. At 64.1° latitude, full moons near the winter solstice rise at their highest point in Reykjavik's sky, while full moons near the summer solstice stay lower on the horizon — this seasonal variation is why winter full moons appear more dramatic from Reykjavik.
How does the moon's phase affect stargazing in Reykjavik?: Moon phase is the single most important factor for stargazing quality at Reykjavik. A full moon (100% illumination) brightens the sky enough to obscure all but the brightest stars and makes deep-sky observation nearly impossible. For the best stargazing in Reykjavik, plan sessions during the 7 days around New Moon when illumination is below 15%. Use MoonSync to find the next New Moon date, then use the Twilight Calculator to check when astronomical darkness begins.
Why does moonrise time change each day in Reykjavik?: The moon rises approximately 50 minutes later each day as seen from Reykjavik because the moon orbits Earth at about 1 km/s, moving approximately 13° eastward per day against the background stars. Since Earth rotates 360° in 24 hours (15°/hour), the extra 13° of rotation takes roughly 50 minutes. This daily delay explains why the moon is sometimes visible in Reykjavik's daytime sky and why moonrise can occur at any hour of the day or night.

30-Day Observation Planner

Date	Sunrise	Sunset	Twilight End	Moon Illum.	Dark Window
Jun 22Today	02:56	00:05	Invalid Date	56%	NaNm
Jun 23	02:57	00:05	Invalid Date	66%	NaNm
Jun 24	02:57	00:05	Invalid Date	75%	NaNm
Jun 25	02:58	00:04	Invalid Date	83%	NaNm
Jun 26	02:59	00:04	Invalid Date	89%	NaNm
Jun 27	03:00	00:03	Invalid Date	94%	NaNm
Jun 28	03:01	00:02	Invalid Date	98%	NaNm
Jun 29	03:03	00:01	Invalid Date	100%	NaNm
Jun 30	03:04	00:00	Invalid Date	100%	NaNm
Jul 1	03:06	23:58	Invalid Date	98%	NaNm
Jul 2	03:08	23:57	Invalid Date	94%	NaNm
Jul 3	03:10	23:55	Invalid Date	89%	NaNm
Jul 4	03:12	23:53	Invalid Date	82%	NaNm
Jul 5	03:14	23:51	Invalid Date	73%	NaNm
Jul 6	03:17	23:49	Invalid Date	63%	NaNm
Jul 7	03:19	23:47	Invalid Date	52%	NaNm
Jul 8	03:22	23:45	Invalid Date	41%	NaNm
Jul 9	03:24	23:43	Invalid Date	30%	NaNm
Jul 10	03:27	23:40	Invalid Date	20%	NaNm
Jul 11	03:30	23:38	Invalid Date	11%	NaNm
Jul 12	03:33	23:35	Invalid Date	5%	NaNm
Jul 13	03:35	23:33	Invalid Date	1%	NaNm
Jul 14	03:38	23:30	Invalid Date	0%	NaNm
Jul 15	03:41	23:27	Invalid Date	2%	NaNm
Jul 16	03:44	23:25	Invalid Date	6%	NaNm
Jul 17	03:47	23:22	Invalid Date	13%	NaNm
Jul 18	03:50	23:19	Invalid Date	21%	NaNm
Jul 19	03:53	23:16	Invalid Date	30%	NaNm
Jul 20	03:57	23:13	Invalid Date	40%	NaNm
Jul 21	04:00	23:10	Invalid Date	50%	NaNm

Moon Phase & Moonrise Times Reykjavik — MoonSync · FastTool — Best Stargazing — Reykjavik

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Tonight's moon phase, moonrise & moonset times for Reykjavik. Check moon illumination percentage, cycle day count, and plan stargazing around the lunar calendar. Free, private, no upload. · Reykjavik moon phase, moonrise & moonset data — 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.