Southern Delta Aquariids 2027: the moon at peak

Jul 31, 2027, 10:00 UTC · Calculated July 26, 2026

6% Excellent — the moon is essentially out of the way.

Peak and moon conditions

Peak (UTC)

Jul 31, 2027, 10:00 UTC

Illumination

Waning crescent

Peak rate (ZHR)

~25/hour

Radiant

Aquarius

Active period

Jul 12 – Aug 23

Peak night by city

For each city: the local time of the peak, and how much of that night is both astronomically dark and free of moonlight.

City	Peak (local time)	Astronomical darkness	Moon-free darkness	Moonrise	Moonset	Rating
Seoul	Sat, Jul 31 19:00	6.5 h	6.2 h	03:39 (+1)	18:04	Good
Tokyo	Sat, Jul 31 19:00	6.7 h	6.4 h	02:51 (+1)	17:05	Good
New York	Sat, Jul 31 06:00	5.9 h	5.2 h	03:17 (+1)	18:15	Good
Los Angeles	Sat, Jul 31 03:00	6.9 h	6.3 h	03:47 (+1)	17:55	Good
London	Sat, Jul 31 11:00	2.6 h	2.4 h	02:10 (+1)	19:04	Good
Madrid	Sat, Jul 31 12:00	6.0 h	6.0 h	05:40 (+1)	20:16	Good
Sydney	Sat, Jul 31 20:00	10.7 h	10.7 h	05:40 (+1)	14:29	Good
São Paulo	Sat, Jul 31 07:00	10.4 h	10.0 h	04:59 (+1)	14:39	Good

Why the moon decides a meteor shower

Meteor rates quoted as ZHR assume a perfectly dark sky with the radiant overhead. Real counts fall off fast with sky brightness, and the moon is the one source of sky brightness that is completely predictable years ahead. A full moon near the peak can cut visible meteors by three quarters even under a cloudless sky. That is why the useful question is not “when is the peak” but “where is the moon at the peak” — which is what this page computes.

Other years

Other meteor showers

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