Dark Sky Odds

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

December is the best month for stargazing at Kalkalpen National Park: on average 32 clear, moonless hours of full darkness, and 18% 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 · Austria

DecemberBest month
257Clear moonless dark hours a year
80%darker than … of Europe’s land
18%Nights with ≥ 2 such hours (December)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January14%2517315%
February19%2814719%
March18%2913322%
April18%249625%
May9%106216%
June2%42614%
July8%85116%
August14%179219%
September17%2112217%
October19%2815318%
November20%3016818%
December18%3217319%

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 pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found0.65
Sky-glow index (own, VIIRS) — at the official map point0.84
Sky-glow index (own, VIIRS) — median across the area0.86
Darkest spot we found47.692, 14.525 (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 202610.820%
9 December 20268–9 December 202611.718%
7 January 20277–8 January 202711.714%
6 February 20276–7 February 202710.719%
8 March 20277–8 March 20279.218%
6 April 20276–7 April 20277.218%
6 May 20275–6 May 20274.89%
4 June 20274–5 June 20272.52%
4 July 20273–4 July 20272.08%
2 August 20271–2 August 20274.514%
31 August 202731 August 2027 – 1 September 20276.814%
30 September 202729–30 September 20278.817%

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 202630%55%6.564°
Geminids *13–14 December 202630%20%10.375°
Geminids *14–15 December 202625%28%9.275°
Quadrantids3–4 January 202722%13%11.871°
Lyrids22–23 April 202742%95%1.376°
Eta Aquariids *5–6 May 202722%0%6.714°
Eta Aquariids *6–7 May 202732%0%6.515°
Perseids *12–13 August 202720%84%3.267°
Perseids *13–14 August 202730%90%2.068°
Orionids21–22 October 202730%59%3.258°
Leonids *17–18 November 202730%82%1.764°
Leonids *18–19 November 202725%73%3.064°
Geminids14–15 December 202725%98%0.075°

* 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