Dark Sky Odds

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

March is the best month for stargazing at Linnansaari National Park: on average 24 clear, moonless hours of full darkness, and 17% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 82% 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
106Clear moonless dark hours a year
82%darker than … of Europe’s land
17%Nights with ≥ 2 such hours (March)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January7%111916%
February8%101427%
March17%2410822%
April4%52222%
May0%00—
June0%00—
July0%00—
August0%0510%
September12%158418%
October11%1814512%
November6%81774%
December9%142047%

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 than82% of Europe’s land
Light pollutionvery dark (darkest 5–20 %)
Sky-glow index (own, VIIRS) — Darkest spot we found0.52
Sky-glow index (own, VIIRS) — at the official map point0.58
Sky-glow index (own, VIIRS) — median across the area0.59
Darkest spot we found62.075, 28.542 (map) — within 5.6 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 202611.26%
9 December 20268–9 December 202612.59%
7 January 20277–8 January 202712.57%
6 February 20276–7 February 202710.88%
8 March 20277–8 March 20278.017%
6 April 20276–7 April 20273.74%
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 20270.00%
31 August 202731 August 2027 – 1 September 20272.50%
30 September 202729–30 September 20277.312%

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 202613%54%7.850°
Geminids *13–14 December 20268%20%12.361°
Geminids *14–15 December 20268%28%10.861°
Quadrantids3–4 January 202713%13%14.574°
Lyrids *22–23 April 202730%96%1.756°
Lyrids *23–24 April 202728%90%3.555°
Eta Aquariids *5–6 May 2027—1%0.0—
Eta Aquariids *6–7 May 2027—0%0.0—
Perseids *12–13 August 202717%84%2.256°
Perseids *13–14 August 202722%90%2.358°
Orionids21–22 October 202723%59%1.344°
Leonids *17–18 November 202713%83%0.250°
Leonids *18–19 November 202713%73%2.050°
Geminids14–15 December 20278%98%0.061°

* 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