Dark Sky Odds

Stargazing at Port-Cros National Park: when is the sky clear and dark?

December is the best month for stargazing at Port-Cros National Park: on average 80 clear, moonless hours of full darkness, and 42% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 61% 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 · France

DecemberBest month
660Clear moonless dark hours a year
61%darker than … of Europe’s land
42%Nights with ≥ 2 such hours (December)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January34%5817633%
February39%6514844%
March36%5713742%
April32%4410741%
May27%348342%
June30%306149%
July42%487465%
August43%6210460%
September39%5912547%
October36%5915738%
November37%6216936%
December42%8018843%

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 than61% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found2.07
Sky-glow index (own, VIIRS) — at the official map point2.42
Sky-glow index (own, VIIRS) — median across the area2.41
Darkest spot we found42.992, 6.408 (map) — within 2.8 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 202610.837%
9 December 20268–9 December 202611.542%
7 January 20277–8 January 202711.534%
6 February 20276–7 February 202710.739%
8 March 20277–8 March 20279.336%
6 April 20276–7 April 20277.732%
6 May 20275–6 May 20275.827%
4 June 20274–5 June 20274.330%
4 July 20273–4 July 20274.242%
2 August 20271–2 August 20275.543%
31 August 202731 August 2027 – 1 September 20277.343%
30 September 202729–30 September 20279.039%

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 202667%55%6.268°
Geminids *13–14 December 202648%20%9.880°
Geminids *14–15 December 202650%28%8.880°
Quadrantids3–4 January 202755%13%11.367°
Lyrids22–23 April 202757%95%1.281°
Eta Aquariids *5–6 May 202752%0%7.320°
Eta Aquariids *6–7 May 202748%1%7.220°
Perseids *12–13 August 202780%84%3.066°
Perseids *13–14 August 202775%90%2.268°
Orionids21–22 October 202745%58%3.563°
Leonids *17–18 November 202767%82%1.868°
Leonids *18–19 November 202767%73%3.268°
Geminids14–15 December 202750%98%0.080°

* 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