Dark Sky Odds

Stargazing at Cilento, Vallo di Diano and Alburni National Park: when is the sky clear and dark?

August is the best month for stargazing at Cilento, Vallo di Diano and Alburni National Park: on average 80 clear, moonless hours of full darkness, and 54% of nights have at least two of them (ERA5, 2006–2025). The darkest spot we found there is darker than 43% 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
526Clear moonless dark hours a year
43%darker than … of Europe’s land
54%Nights with ≥ 2 such hours (August)

Month by month

MonthNights with ≥ 2 such hoursClear moonless dark hoursMoonless dark hoursOf them clear
January20%3017318%
February20%3014720%
March24%3714126%
April22%2911026%
May22%279030%
June36%397652%
July53%658279%
August54%8011072%
September36%5513242%
October30%5115533%
November24%4016624%
December26%4417325%

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 than43% of Europe’s land
Light pollutionnoticeable light glow
Sky-glow index (own, VIIRS) — Darkest spot we found4.95
Sky-glow index (own, VIIRS) — at the official map point22
Sky-glow index (own, VIIRS) — median across the area17
Darkest spot we found40.275, 15.442 (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 202610.724%
9 December 20268–9 December 202611.526%
7 January 20277–8 January 202711.320%
6 February 20276–7 February 202710.520%
8 March 20277–8 March 20279.524%
6 April 20276–7 April 20277.822%
6 May 20276–7 May 20276.322%
4 June 20274–5 June 20275.036%
4 July 20273–4 July 20275.053%
2 August 20271–2 August 20276.054%
31 August 202731 August 2027 – 1 September 20277.754%
30 September 202729–30 September 20279.236%

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 202642%55%6.270°
Geminids *13–14 December 202640%20%9.783°
Geminids *14–15 December 202642%28%8.783°
Quadrantids3–4 January 202733%13%11.065°
Lyrids22–23 April 202732%95%1.284°
Eta Aquariids *5–6 May 202748%0%7.723°
Eta Aquariids *6–7 May 202742%0%7.723°
Perseids *12–13 August 202783%84%3.066°
Perseids *13–14 August 202783%90%2.066°
Orionids21–22 October 202738%59%3.766°
Leonids *17–18 November 202742%82%2.070°
Leonids *18–19 November 202735%73%3.270°
Geminids14–15 December 202742%98%0.083°

* 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