Dark Sky Odds

Stargazing at Sierra de las Nieves National Park: when is the sky clear and dark?

August is the best month for stargazing at Sierra de las Nieves National Park: on average 88 clear, moonless hours of full darkness, and 56% 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
732Clear moonless dark hours a year
41%darker than … of Europe’s land
56%Nights with ≥ 2 such hours (August)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January35%6517337%
February33%5014235%
March32%5314437%
April28%4211736%
May39%5110051%
June49%609266%
July59%809584%
August56%8811875%
September42%6713250%
October32%5115632%
November38%6716840%
December34%5917334%

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 found5.54
Sky-glow index (own, VIIRS) — at the official map point8.13
Sky-glow index (own, VIIRS) — median across the area9.88
Darkest spot we found36.792, -5.008 (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 202610.738%
9 December 20268–9 December 202611.234%
7 January 20277–8 January 202711.235%
6 February 20276–7 February 202710.533%
8 March 20277–8 March 20279.532%
6 April 20276–7 April 20278.228%
6 May 20275–6 May 20276.839%
4 June 20274–5 June 20275.849%
4 July 20273–4 July 20275.759%
2 August 20271–2 August 20276.756%
31 August 202731 August 2027 – 1 September 20278.056%
30 September 202729–30 September 20279.242%

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 202655%55%6.073°
Geminids *13–14 December 202637%21%9.586°
Geminids *14–15 December 202640%29%8.586°
Quadrantids3–4 January 202760%13%10.863°
Lyrids22–23 April 202743%95%1.287°
Eta Aquariids *5–6 May 202768%0%8.025°
Eta Aquariids *6–7 May 202768%1%8.026°
Perseids *12–13 August 202793%84%3.064°
Perseids *13–14 August 202790%91%2.064°
Orionids21–22 October 202747%58%3.869°
Leonids *17–18 November 202755%82%2.273°
Leonids *18–19 November 202757%72%3.373°
Geminids14–15 December 202740%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