Dark Sky Odds

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

December is the best month for stargazing at Vanoise National Park: on average 50 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 65% 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
285Clear moonless dark hours a year
65%darker than … of Europe’s land
25%Nights with ≥ 2 such hours (December)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January19%3117917%
February24%3614825%
March17%2613519%
April14%1810318%
May6%6739%
June5%65610%
July13%156623%
August18%239724%
September16%1912416%
October16%2315515%
November19%3017118%
December25%5018827%

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 than65% of Europe’s land
Light pollutiondark rural sky (darkest 20–50 %)
Sky-glow index (own, VIIRS) — Darkest spot we found1.67
Sky-glow index (own, VIIRS) — at the official map point1.71
Sky-glow index (own, VIIRS) — median across the area1.97
Darkest spot we found45.358, 6.842 (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 202610.819%
9 December 20268–9 December 202611.725%
7 January 20277–8 January 202711.519%
6 February 20276–7 February 202710.724%
8 March 20277–8 March 20279.317%
6 April 20276–7 April 20277.314%
6 May 20275–6 May 20275.56%
4 June 20274–5 June 20273.55%
4 July 20273–4 July 20273.313%
2 August 20271–2 August 20275.218%
31 August 202731 August 2027 – 1 September 20277.218%
30 September 202729–30 September 20279.016%

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 202640%55%6.366°
Geminids *13–14 December 202645%20%10.278°
Geminids *14–15 December 202640%28%9.078°
Quadrantids3–4 January 202730%13%11.570°
Lyrids22–23 April 202732%95%1.378°
Eta Aquariids *5–6 May 202712%0%7.017°
Eta Aquariids *6–7 May 20278%1%6.817°
Perseids *12–13 August 202747%84%3.067°
Perseids *13–14 August 202750%90%2.067°
Orionids21–22 October 202723%58%3.361°
Leonids *17–18 November 202740%82%1.866°
Leonids *18–19 November 202732%73%3.266°
Geminids14–15 December 202740%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