Dark Sky Odds

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

October is the best month for stargazing at Călimani National Park: on average 42 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 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 · Romania

OctoberBest month
285Clear moonless dark hours a year
80%darker than … of Europe’s land
25%Nights with ≥ 2 such hours (October)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January14%2518614%
February14%1914314%
March19%3013622%
April21%259926%
May12%136420%
June6%53316%
July14%165330%
August24%319234%
September21%2812422%
October25%4215527%
November20%3216819%
December11%1818610%

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 pollutionvery dark (darkest 5–20 %)
Sky-glow index (own, VIIRS) — Darkest spot we found0.61
Sky-glow index (own, VIIRS) — at the official map point0.62
Sky-glow index (own, VIIRS) — median across the area0.65
Darkest spot we found47.108, 25.142 (map) — within 8.8 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 202610.820%
9 December 20268–9 December 202611.711%
7 January 20277–8 January 202711.714%
6 February 20276–7 February 202710.714%
8 March 20277–8 March 20279.219%
6 April 20276–7 April 20277.221%
6 May 20276–7 May 20275.012%
4 June 20274–5 June 20272.76%
4 July 20273–4 July 20272.514%
2 August 20271–2 August 20274.724%
31 August 202731 August 2027 – 1 September 20276.824%
30 September 202729–30 September 20278.821%

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 202632%54%6.564°
Geminids *13–14 December 202612%20%10.376°
Geminids *14–15 December 202615%28%9.276°
Quadrantids3–4 January 202722%13%11.771°
Lyrids22–23 April 202750%96%1.276°
Eta Aquariids *5–6 May 202730%0%6.715°
Eta Aquariids *6–7 May 202728%0%6.716°
Perseids *12–13 August 202752%84%3.267°
Perseids *13–14 August 202758%90%2.267°
Orionids21–22 October 202750%59%3.359°
Leonids *17–18 November 202732%83%1.764°
Leonids *18–19 November 202728%73%3.064°
Geminids14–15 December 202715%98%0.076°

* 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