Dark Sky Odds

Stargazing at Rhön Biosphere Reserve: when is the sky clear and dark?

March is the best month for stargazing at Rhön Biosphere Reserve: on average 36 clear, moonless hours of full darkness, and 21% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 72% 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 Reserve · Germany · DarkSky International

MarchBest month
215Clear moonless dark hours a year
72%darker than … of Europe’s land
21%Nights with ≥ 2 such hours (March)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January10%1818710%
February16%2114315%
March21%3613227%
April20%248927%
May9%93726%
June0%00—
July3%31917%
August17%208125%
September20%2811824%
October17%2715418%
November10%141688%
December8%141897%

No astronomical darkness (June): the Sun stays above −18° all night.

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 than72% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found1.10
Sky-glow index (own, VIIRS) — at the official map point1.85
Sky-glow index (own, VIIRS) — median across the area2.28
Darkest spot we found50.558, 10.142 (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 202611.010%
9 December 20268–9 December 202611.88%
7 January 20277–8 January 202711.710%
6 February 20276–7 February 202710.716%
8 March 20277–8 March 20279.221%
6 April 20276–7 April 20276.820%
6 May 20275–6 May 20274.09%
4 June 20274–5 June 20270.00%
4 July 20273–4 July 20270.03%
2 August 20271–2 August 20273.317%
31 August 202731 August 2027 – 1 September 20276.517%
30 September 202729–30 September 20278.520%

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 202613%55%6.761°
Geminids *13–14 December 20265%20%10.772°
Geminids *14–15 December 20265%28%9.572°
Quadrantids3–4 January 20273%13%12.372°
Lyrids22–23 April 202752%95%1.372°
Eta Aquariids *5–6 May 202735%0%6.011°
Eta Aquariids *6–7 May 202735%0%6.011°
Perseids *12–13 August 202745%84%3.266°
Perseids *13–14 August 202743%90%2.268°
Orionids21–22 October 202727%58%3.055°
Leonids *17–18 November 202713%82%1.561°
Leonids *18–19 November 202715%73%3.061°
Geminids14–15 December 20275%98%0.072°

* 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