Dark Sky Odds

Stargazing at Parc Astronòmic Montsec: when is the sky clear and dark?

December is the best month for stargazing at Parc Astronòmic Montsec: on average 74 clear, moonless hours of full darkness, and 40% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 67% 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

dark-sky park · Spain

DecemberBest month
634Clear moonless dark hours a year
67%darker than … of Europe’s land
40%Nights with ≥ 2 such hours (December)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January38%6417237%
February40%6714746%
March35%5414138%
April27%3610834%
May25%318437%
June28%317641%
July40%478059%
August40%5510752%
September36%5613043%
October34%5615536%
November38%6316638%
December40%7417342%

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 than67% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found1.48
Sky-glow index (own, VIIRS) — at the official map point2.15
Sky-glow index (own, VIIRS) — median across the area1.98
Darkest spot we found42.042, 0.725 (map) — within 2.8 km of the Wikidata point (no OSM boundary)

Next new moons

New moonNightMoonless dark hours that nightTypical share of good nights that month
9 November 20268–9 November 202610.838%
9 December 20268–9 December 202611.540%
7 January 20277–8 January 202711.338%
6 February 20276–7 February 202710.540%
8 March 20277–8 March 20279.335%
6 April 20276–7 April 20277.827%
6 May 20275–6 May 20276.025%
4 June 20274–5 June 20274.728%
4 July 20273–4 July 20274.540%
2 August 20271–2 August 20275.740%
31 August 202731 August 2027 – 1 September 20277.540%
30 September 202729–30 September 20279.036%

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 202662%55%6.269°
Geminids *13–14 December 202648%20%9.881°
Geminids *14–15 December 202650%29%8.881°
Quadrantids3–4 January 202757%13%11.266°
Lyrids22–23 April 202752%95%1.282°
Eta Aquariids *5–6 May 202745%0%7.520°
Eta Aquariids *6–7 May 202743%1%7.321°
Perseids *12–13 August 202757%84%3.066°
Perseids *13–14 August 202765%90%2.066°
Orionids21–22 October 202755%58%3.764°
Leonids *17–18 November 202762%82%2.068°
Leonids *18–19 November 202772%72%3.369°
Geminids14–15 December 202750%98%0.081°

* 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