Dark Sky Odds

Stargazing at Atlantic Islands of Galicia National Park: when is the sky clear and dark?

August is the best month for stargazing at Atlantic Islands of Galicia National Park: on average 48 clear, moonless hours of full darkness, and 34% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 41% of Europe’s land (NASA VIIRS 2025).

Data updated: 31 December 2025 · Sources and licences

Calculated 5 November 2026 · cloud cover ERA5 2006–2025 · night lights NASA VIIRS 2025

national park · Spain

AugustBest month
461Clear moonless dark hours a year
41%darker than … of Europe’s land
34%Nights with ≥ 2 such hours (August)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January22%3817522%
February26%4014927%
March24%4013729%
April22%3310830%
May26%318536%
June21%226136%
July32%387650%
August34%4810646%
September30%4712538%
October27%4515829%
November22%3616921%
December24%4318823%

Climate, not a forecast: these are shares of past nights (ERA5 reanalysis, 2006–2025), not a prediction for a particular night. Check a forecast before you go.

Light pollution

Darker than41% of Europe’s land
Light pollutionnoticeable light glow
Sky-glow index (own, VIIRS) — Darkest spot we found5.44
Sky-glow index (own, VIIRS) — at the official map point9.20
Sky-glow index (own, VIIRS) — median across the area9.10
Darkest spot we found42.475, -9.025 (map) — within the OSM boundary

Next new moons

New moonNightMoonless dark hours that nightTypical share of good nights that month
9 November 20268–9 November 202610.822%
9 December 20268–9 December 202611.524%
7 January 20277–8 January 202711.322%
6 February 20276–7 February 202710.526%
8 March 20277–8 March 20279.324%
6 April 20276–7 April 20277.822%
6 May 20275–6 May 20276.026%
4 June 20274–5 June 20274.521%
4 July 20273–4 July 20274.532%
2 August 20271–2 August 20275.734%
31 August 202731 August 2027 – 1 September 20277.534%
30 September 202729–30 September 20279.030%

Hours with the Sun below −18° and the Moon below the horizon, on the night of the new moon, at the darkest spot.

Meteor showers

ShowerPeak nightChance of a clear peak nightMoon litMoonless dark hours (Sun < −12°)Radiant max. height
Leonids17–18 November 202640%55%6.268°
Geminids *13–14 December 202640%21%9.880°
Geminids *14–15 December 202640%29%8.880°
Quadrantids3–4 January 202727%13%11.266°
Lyrids22–23 April 202735%95%1.281°
Eta Aquariids *5–6 May 202737%0%7.520°
Eta Aquariids *6–7 May 202732%1%7.321°
Perseids *12–13 August 202767%84%3.066°
Perseids *13–14 August 202767%91%2.067°
Orionids21–22 October 202738%58%3.764°
Leonids17–18 November 202740%82%2.068°
Geminids14–15 December 202740%97%0.080°

* The peak falls in daylight in Europe, so both neighbouring nights are shown.

Clear peak night: at least 2 hours with ≤ 20 % cloud while the Sun is below −12°, on the same calendar night ± 1 in 2006–2025.

How we calculate