Dark Sky Odds

Stargazing at Petrova Gora: when is the sky clear and dark?

August is the best month for stargazing at Petrova Gora: on average 44 clear, moonless hours of full darkness, and 32% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 55% 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 · Croatia · DarkSky International

AugustBest month
375Clear moonless dark hours a year
55%darker than … of Europe’s land
32%Nights with ≥ 2 such hours (August)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January18%2617315%
February22%3214722%
March27%4313732%
April24%3010329%
May15%177323%
June15%144630%
July26%286544%
August32%449844%
September30%4212634%
October25%3815425%
November19%2916617%
December20%3317319%

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 than55% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found2.93
Sky-glow index (own, VIIRS) — at the official map point4.16
Sky-glow index (own, VIIRS) — median across the area4.14
Darkest spot we found45.258, 15.792 (map) — within 2.8 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 202610.819%
9 December 20268–9 December 202611.520%
7 January 20277–8 January 202711.518%
6 February 20276–7 February 202710.522%
8 March 20277–8 March 20279.327%
6 April 20276–7 April 20277.524%
6 May 20276–7 May 20275.315%
4 June 20274–5 June 20273.715%
4 July 20273–4 July 20273.526%
2 August 20271–2 August 20275.032%
31 August 202731 August 2027 – 1 September 20277.232%
30 September 202729–30 September 20278.830%

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 202622%55%6.566°
Geminids *13–14 December 202632%20%10.078°
Geminids *14–15 December 202632%28%9.078°
Quadrantids3–4 January 202728%13%11.569°
Lyrids22–23 April 202750%95%1.278°
Eta Aquariids *5–6 May 202730%0%7.018°
Eta Aquariids *6–7 May 202727%0%7.018°
Perseids *12–13 August 202773%84%3.267°
Perseids *13–14 August 202768%90%2.268°
Orionids21–22 October 202742%59%3.361°
Leonids *17–18 November 202722%82%1.766°
Leonids *18–19 November 202728%73%3.066°
Geminids14–15 December 202732%98%0.078°

* 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