Dark Sky Odds

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

October is the best month for stargazing at Thingvellir National Park: on average 18 clear, moonless hours of full darkness, and 10% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 36% 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 · Iceland

OctoberBest month
101Clear moonless dark hours a year
36%darker than … of Europe’s land
10%Nights with ≥ 2 such hours (October)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January10%151898%
February10%1414010%
March8%1110011%
April2%11015%
May0%00—
June0%00—
July0%00—
August0%00—
September6%87111%
October10%1814212%
November10%1817710%
December10%162048%

No astronomical darkness (May, June, July, August): 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 than36% of Europe’s land
Light pollutionnoticeable light glow
Sky-glow index (own, VIIRS) — Darkest spot we found6.84
Sky-glow index (own, VIIRS) — at the official map point9.56
Sky-glow index (own, VIIRS) — median across the area9.53
Darkest spot we found64.325, -20.942 (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 202611.210%
9 December 20268–9 December 202612.710%
7 January 20277–8 January 202712.510%
6 February 20276–7 February 202710.710%
8 March 20277–8 March 20277.78%
6 April 20276–7 April 20272.02%
6 May 20275–6 May 20270.00%
4 June 20274–5 June 20270.00%
4 July 20273–4 July 20270.00%
2 August 20271–2 August 20270.00%
31 August 202731 August 2027 – 1 September 20270.00%
30 September 202729–30 September 20277.06%

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 202622%56%7.848°
Geminids *13–14 December 202618%21%12.759°
Geminids *14–15 December 202622%29%11.059°
Quadrantids3–4 January 202728%12%14.873°
Lyrids22–23 April 202717%95%2.550°
Eta Aquariids *5–6 May 2027—0%0.0—
Eta Aquariids *6–7 May 2027—1%0.0—
Perseids *12–13 August 2027—85%0.0—
Perseids *13–14 August 2027—91%0.0—
Orionids21–22 October 202718%57%1.042°
Leonids17–18 November 202722%82%0.048°
Geminids14–15 December 202722%97%0.059°

* 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