Dark Sky Odds

Stargazing at Gantrisch Nature Park: when is the sky clear and dark?

December is the best month for stargazing at Gantrisch Nature Park: on average 49 clear, moonless hours of full darkness, and 24% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 66% 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

International Dark Sky Park · Switzerland · DarkSky International

DecemberBest month
303Clear moonless dark hours a year
66%darker than … of Europe’s land
24%Nights with ≥ 2 such hours (December)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January19%3018117%
February22%3514724%
March24%3713428%
April17%2210022%
May10%126918%
June7%63317%
July11%125621%
August16%199221%
September16%2112417%
October17%2715517%
November20%3217119%
December24%4918926%

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 than66% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found1.57
Sky-glow index (own, VIIRS) — at the official map point3.14
Sky-glow index (own, VIIRS) — median across the area4.54
Darkest spot we found46.692, 7.392 (map) — within 12 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 202610.820%
9 December 20268–9 December 202611.724%
7 January 20277–8 January 202711.719%
6 February 20276–7 February 202710.722%
8 March 20277–8 March 20279.224%
6 April 20276–7 April 20277.317%
6 May 20275–6 May 20275.210%
4 June 20274–5 June 20272.87%
4 July 20273–4 July 20272.711%
2 August 20271–2 August 20274.716%
31 August 202731 August 2027 – 1 September 20276.816%
30 September 202729–30 September 20278.816%

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 202642%55%6.365°
Geminids *13–14 December 202640%20%10.276°
Geminids *14–15 December 202635%28%9.276°
Quadrantids3–4 January 202715%13%11.870°
Lyrids22–23 April 202737%95%1.277°
Eta Aquariids *5–6 May 202727%0%6.816°
Eta Aquariids *6–7 May 202722%1%6.716°
Perseids *12–13 August 202737%84%3.067°
Perseids *13–14 August 202735%90%2.268°
Orionids21–22 October 202723%58%3.359°
Leonids *17–18 November 202742%82%1.765°
Leonids *18–19 November 202737%73%3.065°
Geminids14–15 December 202735%98%0.076°

* 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