Dark Sky Odds

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

December is the best month for stargazing at Triglav National Park: on average 44 clear, moonless hours of full darkness, and 25% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 66% 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 · Slovenia

DecemberBest month
300Clear moonless dark hours a year
66%darker than … of Europe’s land
25%Nights with ≥ 2 such hours (December)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January20%3117318%
February22%3314623%
March24%3713627%
April16%2210022%
May10%96814%
June8%74615%
July10%115918%
August17%239624%
September19%2512520%
October20%3015419%
November19%2916817%
December25%4417325%

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 than66% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found1.60
Sky-glow index (own, VIIRS) — at the official map point1.63
Sky-glow index (own, VIIRS) — median across the area2.05
Darkest spot we found46.358, 13.792 (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 202610.819%
9 December 20268–9 December 202611.725%
7 January 20277–8 January 202711.520%
6 February 20276–7 February 202710.722%
8 March 20277–8 March 20279.324%
6 April 20276–7 April 20277.316%
6 May 20275–6 May 20275.210%
4 June 20274–5 June 20273.08%
4 July 20273–4 July 20272.810%
2 August 20271–2 August 20274.817%
31 August 202731 August 2027 – 1 September 20277.017%
30 September 202729–30 September 20279.019%

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 202637%55%6.565°
Geminids *13–14 December 202647%20%10.277°
Geminids *14–15 December 202643%28%9.077°
Quadrantids3–4 January 202737%13%11.770°
Lyrids22–23 April 202737%95%1.277°
Eta Aquariids *5–6 May 202722%0%6.816°
Eta Aquariids *6–7 May 202725%0%6.816°
Perseids *12–13 August 202743%84%3.267°
Perseids *13–14 August 202733%90%2.068°
Orionids21–22 October 202723%59%3.360°
Leonids *17–18 November 202737%82%1.865°
Leonids *18–19 November 202742%73%3.265°
Geminids14–15 December 202743%98%0.077°

* 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