Dark Sky Odds

Stargazing at Sierra Nevada National and Natural Park: when is the sky clear and dark?

August is the best month for stargazing at Sierra Nevada National and Natural Park: on average 78 clear, moonless hours of full darkness, and 50% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 57% 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
738Clear moonless dark hours a year
57%darker than … of Europe’s land
50%Nights with ≥ 2 such hours (August)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January38%7017041%
February38%5914242%
March34%5514638%
April32%4211536%
May36%4610345%
June43%518461%
July53%729576%
August50%7811767%
September40%6013445%
October35%5615536%
November42%7616845%
December39%7217242%

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 than57% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found2.59
Sky-glow index (own, VIIRS) — at the official map point2.76
Sky-glow index (own, VIIRS) — median across the area3.70
Darkest spot we found37.092, -2.925 (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 202610.742%
9 December 20268–9 December 202611.339%
7 January 20277–8 January 202711.238%
6 February 20276–7 February 202710.538%
8 March 20277–8 March 20279.534%
6 April 20276–7 April 20278.232%
6 May 20275–6 May 20276.836%
4 June 20274–5 June 20275.843%
4 July 20273–4 July 20275.753%
2 August 20271–2 August 20276.550%
31 August 202731 August 2027 – 1 September 20278.050%
30 September 202729–30 September 20279.240%

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%6.073°
Geminids *13–14 December 202657%20%9.586°
Geminids *14–15 December 202658%29%8.586°
Quadrantids3–4 January 202765%13%10.863°
Lyrids22–23 April 202750%95%1.287°
Eta Aquariids *5–6 May 202755%0%8.025°
Eta Aquariids *6–7 May 202757%1%8.026°
Perseids *12–13 August 202788%84%3.064°
Perseids *13–14 August 202788%90%2.064°
Orionids21–22 October 202743%58%3.869°
Leonids *17–18 November 202762%82%2.072°
Leonids *18–19 November 202765%72%3.573°
Geminids14–15 December 202758%98%0.086°

* 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