Dark Sky Odds

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

August is the best month for stargazing at Circeo National Park: on average 76 clear, moonless hours of full darkness, and 53% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 17% 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 · Italy

AugustBest month
592Clear moonless dark hours a year
17%darker than … of Europe’s land
53%Nights with ≥ 2 such hours (August)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January24%3917323%
February29%4314330%
March27%4214130%
April30%3911036%
May25%328737%
June38%427656%
July54%668380%
August53%7610672%
September38%5613242%
October31%4815432%
November26%4416826%
December33%6317336%

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 than17% of Europe’s land
Light pollutionstrong light pollution
Sky-glow index (own, VIIRS) — Darkest spot we found15
Sky-glow index (own, VIIRS) — at the official map point38
Sky-glow index (own, VIIRS) — median across the area43
Darkest spot we found41.225, 13.042 (map) — within 4.2 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 202610.826%
9 December 20268–9 December 202611.533%
7 January 20277–8 January 202711.324%
6 February 20276–7 February 202710.529%
8 March 20277–8 March 20279.527%
6 April 20276–7 April 20277.830%
6 May 20275–6 May 20276.325%
4 June 20274–5 June 20274.838%
4 July 20273–4 July 20274.754%
2 August 20271–2 August 20276.053%
31 August 202731 August 2027 – 1 September 20277.553%
30 September 202729–30 September 20279.238%

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 202645%55%6.269°
Geminids *13–14 December 202653%20%9.782°
Geminids *14–15 December 202655%28%8.882°
Quadrantids3–4 January 202732%13%11.265°
Lyrids22–23 April 202743%95%1.383°
Eta Aquariids *5–6 May 202745%0%7.722°
Eta Aquariids *6–7 May 202752%0%7.723°
Perseids *12–13 August 202788%84%3.065°
Perseids *13–14 August 202788%90%2.066°
Orionids21–22 October 202752%59%3.765°
Leonids *17–18 November 202745%82%1.869°
Leonids *18–19 November 202745%73%3.370°
Geminids14–15 December 202755%98%0.082°

* 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