Stargazing at Sounio National Park: when is the sky clear and dark?
August is the best month for stargazing at Sounio National Park: on average 109 clear, moonless hours of full darkness, and 67% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 14% of Europe’s land (NASA VIIRS 2025).
national park · Greece
Month by month
| Month | Nights with ≥ 2 such hours | Clear moonless dark hours | Moonless dark hours | Of them clear |
|---|---|---|---|---|
| January | 40% | 73 | 177 | 41% |
| February | 35% | 56 | 142 | 40% |
| March | 41% | 66 | 142 | 46% |
| April | 42% | 63 | 118 | 54% |
| May | 45% | 60 | 97 | 61% |
| June | 60% | 75 | 92 | 81% |
| July | 66% | 92 | 95 | 97% |
| August | 67% | 109 | 116 | 94% |
| September | 58% | 96 | 131 | 74% |
| October | 50% | 87 | 156 | 56% |
| November | 43% | 80 | 168 | 47% |
| December | 38% | 69 | 180 | 38% |
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 | 14% of Europe’s land |
|---|---|
| Light pollution | strong light pollution |
| Sky-glow index (own, VIIRS) — Darkest spot we found | 18 |
| Sky-glow index (own, VIIRS) — at the official map point | 37 |
| Sky-glow index (own, VIIRS) — median across the area | 36 |
| Darkest spot we found | 37.642, 24.025 (map) — within 3.3 km of the Wikidata point (no 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 | 10.7 | 43% |
| 9 December 2026 | 8–9 December 2026 | 11.3 | 38% |
| 7 January 2027 | 7–8 January 2027 | 11.2 | 40% |
| 6 February 2027 | 6–7 February 2027 | 10.5 | 35% |
| 8 March 2027 | 7–8 March 2027 | 9.3 | 41% |
| 6 April 2027 | 6–7 April 2027 | 8.2 | 42% |
| 6 May 2027 | 6–7 May 2027 | 6.8 | 45% |
| 4 June 2027 | 4–5 June 2027 | 5.7 | 60% |
| 4 July 2027 | 3–4 July 2027 | 5.5 | 66% |
| 2 August 2027 | 1–2 August 2027 | 6.5 | 67% |
| 31 August 2027 | 31 August 2027 – 1 September 2027 | 8.0 | 67% |
| 30 September 2027 | 29–30 September 2027 | 9.3 | 58% |
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 | 58% | 54% | 6.0 | 72° |
| Geminids * | 13–14 December 2026 | 63% | 20% | 9.5 | 85° |
| Geminids * | 14–15 December 2026 | 58% | 28% | 8.5 | 85° |
| Quadrantids | 3–4 January 2027 | 68% | 13% | 10.8 | 62° |
| Lyrids | 22–23 April 2027 | 52% | 95% | 1.2 | 86° |
| Eta Aquariids * | 5–6 May 2027 | 73% | 0% | 8.0 | 26° |
| Eta Aquariids * | 6–7 May 2027 | 72% | 0% | 7.8 | 25° |
| Perseids * | 12–13 August 2027 | 100% | 84% | 3.0 | 64° |
| Perseids * | 13–14 August 2027 | 98% | 90% | 2.0 | 64° |
| Orionids | 21–22 October 2027 | 78% | 59% | 3.8 | 68° |
| Leonids * | 17–18 November 2027 | 58% | 83% | 2.0 | 72° |
| Leonids * | 18–19 November 2027 | 62% | 73% | 3.2 | 72° |
| Geminids | 14–15 December 2027 | 58% | 98% | 0.0 | 85° |
* 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.