Dark Sky Odds

Stargazing at National Marine Park of Zakynthos: when is the sky clear and dark?

August is the best month for stargazing at National Marine Park of Zakynthos: on average 107 clear, moonless hours of full darkness, and 66% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 7% 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 · Greece

AugustBest month
730Clear moonless dark hours a year
7%darker than … of Europe’s land
66%Nights with ≥ 2 such hours (August)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January23%3617321%
February27%4114827%
March30%4514032%
April39%5511946%
May39%509453%
June57%729178%
July66%909594%
August66%10711792%
September46%7413057%
October38%6415840%
November31%5016430%
December27%4818726%

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 than7% of Europe’s land
Light pollutionstrong light pollution
Sky-glow index (own, VIIRS) — Darkest spot we found37
Sky-glow index (own, VIIRS) — at the official map point111
Sky-glow index (own, VIIRS) — median across the area96
Darkest spot we found37.758, 20.942 (map) — within 5.8 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 202610.531%
9 December 20268–9 December 202611.227%
7 January 20277–8 January 202711.223%
6 February 20276–7 February 202710.527%
8 March 20277–8 March 20279.530%
6 April 20276–7 April 20278.239%
6 May 20276–7 May 20276.739%
4 June 20274–5 June 20275.757%
4 July 20273–4 July 20275.566%
2 August 20271–2 August 20276.566%
31 August 202731 August 2027 – 1 September 20278.066%
30 September 202729–30 September 20279.246%

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 202640%54%6.072°
Geminids *13–14 December 202640%20%9.785°
Geminids *14–15 December 202645%28%8.785°
Quadrantids3–4 January 202733%13%10.762°
Lyrids22–23 April 202750%95%1.286°
Eta Aquariids *5–6 May 202773%0%8.026°
Eta Aquariids *6–7 May 202772%0%8.026°
Perseids *12–13 August 202795%84%3.064°
Perseids *13–14 August 202797%90%2.064°
Orionids21–22 October 202758%59%3.868°
Leonids *17–18 November 202740%82%2.071°
Leonids *18–19 November 202738%73%3.273°
Geminids14–15 December 202745%98%0.085°

* 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