It is now abundantly clear that this was likely the most widespread outbreak of noctilucent clouds ever observed over Europe.

Noctilucent clouds were reported from Poland to the UK and from Denmark to Italy and Croatia – and everywhere in between. Not only that: while typically NLCs are only visible low in the northern sky, they covered half the sky and more across many locations. In some places NLCs were so bright that people could read under their light! This unprecedented display continues the exceptionally active NLC season of 2019: the first NLCs were reported as early as May 28th and several major displays had already happened in the first three weeks of June.

Noctilucent cloud displays were noted across Europe on June 8th, 10th and 11th, with a major display on the night of June 12/13th and another one on June 17/18th. Noctilucent clouds were seen as far south as Romania. On June 9th noctilucent clouds were spotted in California, as far south as 33 °N – a new record! Combined with the historic June 21st outbreak, this is certainly the most active NLC season on record.

Noctilucent clouds – the most unusual, extreme clouds on Earth


Stay alert for noctilucent clouds in the next several weeks. Watch the northern skies in evening and morning twilight. Any noctilucent clouds will be bright white or bluish, while other clouds (lower down in the troposphere) will be already dark. Noctilucent clouds come in many different shapes and forms, from tenuous veils, to long streaking, parallel bands, closely spaced waves and ripples and sometimes even whirls. In the evening watch the sky starting about 20-30 minutes after sunset and keep watching for the next hour or so. In the morning, go out about an hour and a half before sunrise and watch the northern sky. In this year’s NLC season you will get lucky sooner or later and maybe you will see a big outbreak. Good luck!

Veltruby, near Kolín, Czech Republic. Photo: Honza Jeřábek‎.

Edinburgh, UK. Photo: Aldo Marchesi‎.

Over the Baltic sea from Grzybowo, Poland. Photo: Leszek Bartczak‎.

Pecs, Hungary. Photo: Andrea Szabo‎‎‎.

Němčice, Czech Republic. Photo: Jitka Rösslerová‎‎‎‎‎.

Saarland, Germany. Photo: Frank Becker‎.

Friesland, the Netherlandsa. Photo: Coen de Lange‎.

Almere, the Netherlands. Photo: Calvin Musch‎‎.

Aš, Czech Republic. Photo: Dominik Erban‎‎‎.

Groningen, the Netherlands. Note the reddish color of the upper part of NLCs – this part is illuminated by the evening reds refracting through the atmosphere. Photo: Dennis Veninga‎‎.

Western Slovenia. Photo: Marko Korošec.

Bavaria, Germany. Photo: Josef Zeitler‎‎‎.

Umag, Croatia. Photo: Maja Kraljik.

Xanten, Germany. Photo: Andreas Esch‎.

Ipswich, UK. Photo: Carl Harlott.

Czech Republic. Photo: Lukáš Vobecký‎‎.

Zwolle, the Netherlands. Photo: Jan van Dijk‎‎‎‎‎.

Königswinter, Germany. Photo: Thomsen Hillary‎‎‎.

South West, England. Photo: Richard Cliff.

Denmark. Photo: Vincent Bakker.

Alkmaar, the Netherlands. Photo: Petroula Dekker.

Luxembourg. Photo: Kata Strofe‎.

Steenderen, the Netherland. Photo: Erwin Klein‎‎‎‎.

The Netherlands. Photo: Esther Boerma-Racké‎.

Sønderborg, Denmark. Photo: Kjeld Jensen‎‎.

Sopot, Poland. Photo: Mateusz Rękas.

Denmark. Photo: Jose Rodriguez.

Poznan, Poland. Photo: Patrycja Długosz‎‎‎.

Barry, Wales, UK. Photo: Philip Dawson.