Dark Sky Odds

Stargazing at Aigüestortes i Estany de Sant Maurici National Park: when is the sky clear and dark?

December is the best month for stargazing at Aigüestortes i Estany de Sant Maurici National Park: on average 42 clear, moonless hours of full darkness, and 22% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 80% 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

DecemberBest month
312Clear moonless dark hours a year
80%darker than … of Europe’s land
22%Nights with ≥ 2 such hours (December)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January18%3017317%
February20%3314722%
March14%2414117%
April10%1410713%
May8%108212%
June14%157719%
July22%268032%
August24%3110530%
September17%2712921%
October20%3015620%
November19%3016618%
December22%4217324%

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 than80% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found0.64
Sky-glow index (own, VIIRS) — at the official map point0.66
Sky-glow index (own, VIIRS) — median across the area0.73
Darkest spot we found42.558, 0.975 (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 202610.819%
9 December 20268–9 December 202611.522%
7 January 20277–8 January 202711.518%
6 February 20276–7 February 202710.520%
8 March 20277–8 March 20279.314%
6 April 20276–7 April 20277.810%
6 May 20275–6 May 20276.08%
4 June 20274–5 June 20274.314%
4 July 20273–4 July 20274.322%
2 August 20271–2 August 20275.724%
31 August 202731 August 2027 – 1 September 20277.524%
30 September 202729–30 September 20279.017%

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 202643%55%6.268°
Geminids *13–14 December 202633%20%9.880°
Geminids *14–15 December 202633%29%8.880°
Quadrantids3–4 January 202733%13%11.266°
Lyrids22–23 April 202718%95%1.281°
Eta Aquariids *5–6 May 202717%0%7.320°
Eta Aquariids *6–7 May 202717%1%7.321°
Perseids *12–13 August 202738%84%3.067°
Perseids *13–14 August 202740%90%2.067°
Orionids21–22 October 202725%58%3.763°
Leonids *17–18 November 202743%82%2.068°
Leonids *18–19 November 202747%72%3.268°
Geminids14–15 December 202733%98%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