Stargazing at Swiss National Park: when is the sky clear and dark?
December is the best month for stargazing at Swiss National Park: on average 44 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 80% of Europe’s land (NASA VIIRS 2025).
national park · Switzerland
Month by month
| Month | Nights with ≥ 2 such hours | Clear moonless dark hours | Moonless dark hours | Of them clear |
|---|---|---|---|---|
| January | 17% | 28 | 186 | 15% |
| February | 21% | 31 | 142 | 22% |
| March | 19% | 29 | 136 | 21% |
| April | 14% | 17 | 101 | 17% |
| May | 7% | 7 | 66 | 11% |
| June | 5% | 4 | 35 | 12% |
| July | 8% | 8 | 56 | 14% |
| August | 10% | 12 | 93 | 13% |
| September | 12% | 14 | 124 | 11% |
| October | 15% | 21 | 155 | 14% |
| November | 17% | 28 | 168 | 16% |
| December | 22% | 44 | 186 | 24% |
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 than | 80% of Europe’s land |
|---|---|
| Light pollution | very dark (darkest 5–20 %) |
| Sky-glow index (own, VIIRS) — Darkest spot we found | 0.61 |
| Sky-glow index (own, VIIRS) — at the official map point | 1.50 |
| Sky-glow index (own, VIIRS) — median across the area | 0.75 |
| Darkest spot we found | 46.725, 10.142 (map) — within the OSM boundary |
Next new moons
| New moon | Night | Moonless dark hours that night | Typical share of good nights that month |
|---|---|---|---|
| 9 November 2026 | 8–9 November 2026 | 10.8 | 17% |
| 9 December 2026 | 8–9 December 2026 | 11.7 | 22% |
| 7 January 2027 | 7–8 January 2027 | 11.7 | 17% |
| 6 February 2027 | 6–7 February 2027 | 10.7 | 21% |
| 8 March 2027 | 7–8 March 2027 | 9.2 | 19% |
| 6 April 2027 | 6–7 April 2027 | 7.3 | 14% |
| 6 May 2027 | 5–6 May 2027 | 5.0 | 7% |
| 4 June 2027 | 4–5 June 2027 | 2.8 | 5% |
| 4 July 2027 | 3–4 July 2027 | 2.7 | 8% |
| 2 August 2027 | 1–2 August 2027 | 4.7 | 10% |
| 31 August 2027 | 31 August 2027 – 1 September 2027 | 6.8 | 10% |
| 30 September 2027 | 29–30 September 2027 | 8.8 | 12% |
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
| Shower | Peak night | Chance of a clear peak night | Moon lit | Moonless dark hours (Sun < −12°) | Radiant max. height |
|---|---|---|---|---|---|
| Leonids | 17–18 November 2026 | 33% | 55% | 6.5 | 65° |
| Geminids * | 13–14 December 2026 | 43% | 20% | 10.2 | 76° |
| Geminids * | 14–15 December 2026 | 43% | 28% | 9.2 | 76° |
| Quadrantids | 3–4 January 2027 | 22% | 13% | 11.7 | 71° |
| Lyrids | 22–23 April 2027 | 33% | 95% | 1.3 | 77° |
| Eta Aquariids * | 5–6 May 2027 | 22% | 0% | 6.7 | 15° |
| Eta Aquariids * | 6–7 May 2027 | 20% | 0% | 6.7 | 16° |
| Perseids * | 12–13 August 2027 | 28% | 84% | 3.0 | 67° |
| Perseids * | 13–14 August 2027 | 25% | 90% | 2.2 | 68° |
| Orionids | 21–22 October 2027 | 25% | 58% | 3.3 | 59° |
| Leonids * | 17–18 November 2027 | 33% | 82% | 1.7 | 65° |
| Leonids * | 18–19 November 2027 | 30% | 73% | 3.0 | 65° |
| Geminids | 14–15 December 2027 | 43% | 98% | 0.0 | 76° |
* 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.