Dark Sky Odds

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

March is the best month for stargazing at Nuuksio National Park: on average 33 clear, moonless hours of full darkness, and 22% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 15% 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 · Finland

MarchBest month
154Clear moonless dark hours a year
15%darker than … of Europe’s land
22%Nights with ≥ 2 such hours (March)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January8%141897%
February11%1614411%
March22%3311229%
April9%103230%
May0%00—
June0%00—
July0%00—
August2%21414%
September16%199221%
October17%3014820%
November9%151748%
December10%171929%

No astronomical darkness (May, June, July): 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 than15% of Europe’s land
Light pollutionstrong light pollution
Sky-glow index (own, VIIRS) — Darkest spot we found18
Sky-glow index (own, VIIRS) — at the official map point19
Sky-glow index (own, VIIRS) — median across the area22
Darkest spot we found60.342, 24.492 (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 202611.09%
9 December 20268–9 December 202612.310%
7 January 20277–8 January 202712.38%
6 February 20276–7 February 202710.711%
8 March 20277–8 March 20278.322%
6 April 20276–7 April 20274.59%
6 May 20276–7 May 20270.00%
4 June 20274–5 June 20270.00%
4 July 20273–4 July 20270.00%
2 August 20271–2 August 20270.02%
31 August 202731 August 2027 – 1 September 20273.52%
30 September 202729–30 September 20277.716%

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 202618%54%7.552°
Geminids *13–14 December 202615%20%12.063°
Geminids *14–15 December 202613%28%10.563°
Quadrantids3–4 January 202718%13%14.274°
Lyrids *22–23 April 202748%95%1.759°
Lyrids *23–24 April 202745%90%3.058°
Eta Aquariids *5–6 May 202742%0%2.3-6°
Eta Aquariids *6–7 May 202742%0%2.0-6°
Perseids *12–13 August 202737%84%3.560°
Perseids *13–14 August 202740%90%2.361°
Orionids21–22 October 202727%59%1.846°
Leonids *17–18 November 202718%83%0.552°
Leonids *18–19 November 202715%73%2.252°
Geminids14–15 December 202713%98%0.063°

* 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