Dark Sky Odds

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

October is the best month for stargazing at Piatra Craiului National Park: on average 45 clear, moonless hours of full darkness, and 26% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 64% 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 · Romania

OctoberBest month
342Clear moonless dark hours a year
64%darker than … of Europe’s land
26%Nights with ≥ 2 such hours (October)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January20%3318518%
February18%2314316%
March23%3413725%
April19%2310322%
May11%137317%
June10%114822%
July20%226434%
August27%379838%
September26%3812630%
October26%4515529%
November18%3216819%
December18%3218517%

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 than64% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found1.80
Sky-glow index (own, VIIRS) — at the official map point2.86
Sky-glow index (own, VIIRS) — median across the area3.29
Darkest spot we found45.525, 25.125 (map) — within 6.9 km of the Wikidata point (no 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 202611.718%
7 January 20277–8 January 202711.720%
6 February 20276–7 February 202710.718%
8 March 20277–8 March 20279.223%
6 April 20276–7 April 20277.519%
6 May 20276–7 May 20275.311%
4 June 20274–5 June 20273.510%
4 July 20273–4 July 20273.320%
2 August 20271–2 August 20275.027%
31 August 202731 August 2027 – 1 September 20277.227%
30 September 202729–30 September 20278.826%

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 202635%54%6.566°
Geminids *13–14 December 202632%20%10.278°
Geminids *14–15 December 202633%28%9.278°
Quadrantids3–4 January 202740%13%11.769°
Lyrids22–23 April 202737%96%1.278°
Eta Aquariids *5–6 May 202730%0%7.017°
Eta Aquariids *6–7 May 202730%0%7.018°
Perseids *12–13 August 202755%84%3.267°
Perseids *13–14 August 202758%90%2.268°
Orionids21–22 October 202750%59%3.360°
Leonids *17–18 November 202735%83%1.766°
Leonids *18–19 November 202725%73%3.066°
Geminids14–15 December 202733%98%0.078°

* 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