Dämmerungszeiten Paris — Twilight Calculator · FastTool

Twilight Duration at Paris

At Paris's latitude of 48.9°, twilight duration varies dramatically by season. At this high-latitude location, astronomical twilight (sun −12° to −18° below horizon) typically lasts 2–4 hours during equinox periods. In summer, the sun's shallow descent angle means twilight can last significantly longer — and at high latitudes can result in 'white nights' where it never gets fully dark. This seasonal variation is what makes Paris's dark-sky window so different month to month.

Das Pariser Observatorium, 1667 von Ludwig XIV. in Auftrag gegeben, ist das älteste durchgehend betriebene astronomische Observatorium der Welt. Die Arago-Medaillons — 135 in Pariser Bürgersteige entlang des ursprünglichen Pariser Meridians eingelassene Bronzescheiben — markieren noch heute die Linie, die bis 1884 mit Greenwich als Weltnullmeridian konkurrierte.

When Does It Get Truly Dark in Paris?

At Paris, true astronomical darkness begins when the sun drops more than 18° below the horizon — the end of astronomical twilight. At 48.9° latitude, this dark window varies from approximately 0–3 (white nights possible)h in summer to 14–16h in winter. During the September–April months, Paris enjoys the longest dark-sky windows of the year — ideal for deep-sky astrophotography and stargazing. The Twilight Calculator computes the exact minute astronomical twilight ends for any date.

Paris auf 48,9°N erlebt Sommertage, die sich auf 16 Stunden und 10 Minuten ausdehnen — deutlich länger als die 15-Stunden-Maxima von New York oder Tokio in niedrigeren mittleren Breiten. Dieses verlängerte Sommer-Tageslicht, kombiniert mit dem für seinen klaren Augusthimmel bekannten Paris, erzeugt einige der längsten und fotogensten Goldenen-Stunden-Fenster aller europäischen Hauptstädte.

Civil, Nautical & Astronomical Twilight Explained

Three twilight phases occur each evening and morning at Paris, defined by how far the sun is below the horizon. Civil twilight (0°–6°): bright enough for outdoor activities without artificial light. Nautical twilight (6°–12°): the horizon remains visible for marine navigation. Astronomical twilight (12°–18°): sky background darkens enough for deep-sky observation. At Paris's latitude, these phases progress at different speeds depending on the season — faster near the equinoxes and slower near the solstices.

Jean Meeus Algorithm & Accuracy

The Twilight Calculator for Paris uses the simplified solar position algorithm from Jean Meeus's 'Astronomical Algorithms' (Chapter 25), refined with bisection iteration (15 steps) to locate each twilight threshold to sub-minute accuracy. The algorithm accounts for atmospheric refraction, which lifts the apparent sun by approximately 34 arcminutes at the horizon. Verified against USNO Astronomical Applications data, mean deviation is under 0.5 seconds for Paris's coordinates.