Dark Sky Odds

Stargazing at Gotska Sandön National Park: when is the sky clear and dark?

March is the best month for stargazing at Gotska Sandön National Park: on average 34 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 99.8% 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 · Sweden

MarchBest month
167Clear moonless dark hours a year
99.8%darker than … of Europe’s land
22%Nights with ≥ 2 such hours (March)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January9%131827%
February14%1914413%
March22%3411929%
April15%164833%
May0%00—
June0%00—
July0%00—
August5%52519%
September19%2610126%
October12%1914812%
November11%1717710%
December12%1918910%

No astronomical darkness (May, June, July): the Sun stays above −18° all night.

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 than99.8% of Europe’s land
Light pollutionamong the darkest 5 % of Europe
Sky-glow index (own, VIIRS) — Darkest spot we found0.009
Sky-glow index (own, VIIRS) — at the official map point0.013
Sky-glow index (own, VIIRS) — median across the area0.013
Darkest spot we found58.375, 19.308 (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 202611.011%
9 December 20268–9 December 202612.312%
7 January 20277–8 January 202712.29%
6 February 20276–7 February 202710.714%
8 March 20277–8 March 20278.522%
6 April 20276–7 April 20275.015%
6 May 20276–7 May 20270.00%
4 June 20274–5 June 20270.00%
4 July 20273–4 July 20270.00%
2 August 20271–2 August 20270.05%
31 August 202731 August 2027 – 1 September 20274.35%
30 September 202729–30 September 20277.819%

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 202625%55%7.354°
Geminids *13–14 December 202615%20%11.565°
Geminids *14–15 December 202615%28%10.265°
Quadrantids3–4 January 202725%13%13.874°
Lyrids *22–23 April 202752%95%1.562°
Lyrids *23–24 April 202743%90%2.861°
Eta Aquariids *5–6 May 202755%0%3.5-1°
Eta Aquariids *6–7 May 202752%0%3.50°
Perseids *12–13 August 202728%84%3.362°
Perseids *13–14 August 202730%90%2.364°
Orionids21–22 October 202720%59%2.248°
Leonids *17–18 November 202725%82%0.854°
Leonids *18–19 November 202718%73%2.354°
Geminids14–15 December 202715%98%0.065°

* 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