Dark Sky Odds

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

September is the best month for stargazing at National Park Thayatal: on average 42 clear, moonless hours of full darkness, and 28% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 57% 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

SeptemberBest month
303Clear moonless dark hours a year
57%darker than … of Europe’s land
28%Nights with ≥ 2 such hours (September)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January14%2217313%
February20%2814619%
March26%4213331%
April25%329434%
May13%145526%
June0%1624%
July7%93824%
August25%308934%
September28%4212035%
October21%3615323%
November16%2417014%
December13%2218512%

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 than57% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found2.57
Sky-glow index (own, VIIRS) — at the official map point3.24
Sky-glow index (own, VIIRS) — median across the area2.87
Darkest spot we found48.842, 15.842 (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 202610.816%
9 December 20268–9 December 202611.813%
7 January 20277–8 January 202711.714%
6 February 20276–7 February 202710.820%
8 March 20277–8 March 20279.226%
6 April 20276–7 April 20277.025%
6 May 20276–7 May 20274.513%
4 June 20274–5 June 20271.30%
4 July 20273–4 July 20270.87%
2 August 20271–2 August 20274.025%
31 August 202731 August 2027 – 1 September 20276.725%
30 September 202729–30 September 20278.728%

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 202628%55%6.563°
Geminids *13–14 December 202615%20%10.574°
Geminids *14–15 December 202620%28%9.374°
Quadrantids3–4 January 202728%13%12.072°
Lyrids22–23 April 202758%95%1.374°
Eta Aquariids *5–6 May 202735%0%6.313°
Eta Aquariids *6–7 May 202743%0%6.314°
Perseids *12–13 August 202738%84%3.267°
Perseids *13–14 August 202740%90%2.268°
Orionids21–22 October 202735%59%3.257°
Leonids *17–18 November 202728%82%1.763°
Leonids *18–19 November 202723%73%3.063°
Geminids14–15 December 202720%98%0.074°

* 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