Moon data for Porto

Moon Phase & Moonrise Times Porto — MoonSync · FastTool

How Moon Phases Work at Porto's Latitude

Moon Phases Visible from Porto

From Porto at latitude 41.2°, 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, Porto's mid-latitude latitude affects the moon's maximum altitude in the sky. The moon can reach up to 77.4° altitude when crossing the meridian near summer solstice, and only 20.2° near winter solstice. This seasonal variation determines how high the moon appears above Porto's horizon and affects lunar photography planning.

Porto lies within the southern half of the August 12, 2026 total solar eclipse path — totality will last approximately 1 minute 45 seconds over the city's iconic Dom Luís I Bridge and Douro River valley. The narrow streets of the UNESCO-listed Ribeira district will fall into an eerie midday darkness, as the Moon's shadow races inland from the Atlantic at over 2,000 km/h.

NASA Moon Phase Reference

Moonrise & Moonset Times at Porto

The moon rises approximately 50 minutes later each day as seen from Porto. 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 Porto's latitude (41.2°), 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 Porto using real-time ephemeris data.

Porto at 41.2°N is bathed in Atlantic light — its famously golden late-afternoon sun, filtered through maritime haze, has inspired painters and photographers for centuries. The city's west-facing position at the mouth of the Douro River means every sunset is a spectacle framed by the river, the ocean, and the terraced hills of Vila Nova de Gaia across the water.

USNO Moonrise Data

Moon Illumination & Porto's Dark-Sky Planning

For stargazing and astrophotography in Porto, 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 41.2° 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 Porto.

IAU — Observing Conditions

Lunar Data Accuracy for Porto

MoonSync computes moon phase, illumination, moonrise/moonset times, and lunar age for Porto using real-time ephemeris data. Phase illumination is accurate to ±1%. Moonrise and moonset times are calculated from Porto's precise coordinates (41.2°, -8.6°) 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
23%Illumination
11:53Moonrise
20:35Moonset
GoodPhoto Window

Tonight's Moon Phase

Waxing CrescentLIVE

23.1%

Moon age4.0 days / 29.53
Synodic cycle13.7%

Observer Location

Moonrise11:53 AM
Moonset08:35 PM
Moon is above the horizon

Astrophotography Planning

Good

Good deep-sky nights around the new Moon — schedule sessions when the Moon is below the horizon.

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 Porto

What is the moon phase tonight in Porto?
Tonight's moon phase for Porto is displayed in real time on MoonSync. The page loads with Porto's coordinates (41.2°, -8.6°) and shows the current moon illumination percentage, lunar age (days since new moon), moonrise and moonset times, and the moon's position above Porto's horizon. All calculations run client-side — no location data is sent anywhere.
When is the next full moon visible from Porto?
MoonSync's lunar calendar shows the full moon phase progression for any date and location, including Porto. Full moons occur approximately every 29.53 days. At 41.2° latitude, full moons near the winter solstice rise at their highest point in Porto'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 Porto.
How does the moon's phase affect stargazing in Porto?
Moon phase is the single most important factor for stargazing quality at Porto. 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 Porto, 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 Porto?
The moon rises approximately 50 minutes later each day as seen from Porto 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 Porto's daytime sky and why moonrise can occur at any hour of the day or night.

30-Day Observation Planner

DateSunriseSunsetTwilight EndMoon Illum.Dark Window
Oct 15Today06:4617:5618:5522%10h 51m
Oct 1606:4717:5418:5431%10h 54m
Oct 1706:4917:5318:5240%10h 56m
Oct 1806:5017:5118:5149%10h 59m
Oct 1906:5117:5018:4958%11h 1m
Oct 2006:5217:4818:4868%11h 4m
Oct 2106:5317:4718:4777%11h 6m
Oct 2206:5417:4518:4585%11h 9m
Oct 2306:5517:4418:4491%11h 11m
Oct 2406:5717:4218:4396%11h 14m
Oct 2506:5817:4118:4199%11h 16m
Oct 2606:5917:3918:40100%11h 18m
Oct 2707:0017:3818:3998%11h 21m
Oct 2807:0117:3718:3893%11h 23m
Oct 2907:0217:3618:3686%11h 25m
Oct 3007:0417:3418:3577%11h 28m
Oct 3107:0517:3318:3467%11h 30m
Nov 107:0617:3218:3355%11h 32m
Nov 207:0717:3018:3244%11h 34m
Nov 307:0817:2918:3132%11h 36m
Nov 407:1017:2818:3022%11h 39m
Nov 507:1117:2718:2914%11h 41m
Nov 607:1217:2618:287%11h 43m
Nov 707:1317:2518:273%11h 45m
Nov 807:1417:2418:261%11h 47m
Nov 907:1617:2318:250%11h 49m
Nov 1007:1717:2218:242%11h 51m
Nov 1107:1817:2118:235%11h 53m
Nov 1207:1917:2018:2210%11h 55m
Nov 1307:2117:1918:2116%11h 57m

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

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

All tools on fastool.io run entirely in your browser — zero data leaves your device. No personal data is collected, stored, or transmitted to any server. Solar calculations use SunCalc.js; lunar data uses JPL DE440 ephemeris; coordinate transforms use publicly documented EPSG/OGC standards. This site requires no signup, no account, and no cloud processing.