Dark Sky Odds

Stargazing at Una National Park: when is the sky clear and dark?

August is the best month for stargazing at Una National Park: on average 51 clear, moonless hours of full darkness, and 38% 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).

Data updated: 31 December 2025 · Sources and licences

Calculated 5 November 2026 · cloud cover ERA5 2006–2025 · night lights NASA VIIRS 2025

national park · Bosnia and Herzegovina

AugustBest month
382Clear moonless dark hours a year
80%darker than … of Europe’s land
38%Nights with ≥ 2 such hours (August)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January14%2417314%
February19%2814719%
March22%3813927%
April22%2910428%
May18%207826%
June16%164932%
July33%367051%
August38%5110051%
September29%4412635%
October24%3715524%
November18%2716516%
December19%3317219%

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 than80% of Europe’s land
Light pollutionvery dark (darkest 5–20 %)
Sky-glow index (own, VIIRS) — Darkest spot we found0.61
Sky-glow index (own, VIIRS) — at the official map point1.66
Sky-glow index (own, VIIRS) — median across the area1.05
Darkest spot we found44.442, 16.208 (map) — within the OSM boundary

Next new moons

New moonNightMoonless dark hours that nightTypical share of good nights that month
9 November 20268–9 November 202610.818%
9 December 20268–9 December 202611.519%
7 January 20277–8 January 202711.514%
6 February 20276–7 February 202710.719%
8 March 20277–8 March 20279.322%
6 April 20276–7 April 20277.522%
6 May 20276–7 May 20275.518%
4 June 20274–5 June 20273.816%
4 July 20273–4 July 20273.833%
2 August 20271–2 August 20275.238%
31 August 202731 August 2027 – 1 September 20277.338%
30 September 202729–30 September 20279.029%

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%6.366°
Geminids *13–14 December 202632%20%10.078°
Geminids *14–15 December 202627%28%9.079°
Quadrantids3–4 January 202725%13%11.569°
Lyrids22–23 April 202747%95%1.279°
Eta Aquariids *5–6 May 202732%0%7.218°
Eta Aquariids *6–7 May 202728%0%7.219°
Perseids *12–13 August 202775%84%3.267°
Perseids *13–14 August 202773%90%2.267°
Orionids21–22 October 202730%59%3.562°
Leonids *17–18 November 202722%82%1.866°
Leonids *18–19 November 202728%73%3.067°
Geminids14–15 December 202727%98%0.079°

* 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