This is a good time of year to look up at the sky after sunset and before sunrise. Around the start of the astronomical summer on June 21st, there is a good chance that you will encounter the weather phenomenon noctilucent clouds.

The shiny clouds could be seen all over the Netherlands on Wednesday night and Thursday morning.
NLCs over The Netherlands
© Via Twitter@pcb1970pcb
Noctilucent clouds over Uithoorn, Netherlands on June 13-14th, 2019.
Noctilucent clouds are created by tiny ice crystals forming on dust particles. "When the sun is down for us and it gets dark, the clouds are still lit by the sun. This makes it look like these clouds are shining in the dark", Weerplaza writes about the phenomenon. Because it is often quite windy in the Netherlands this time of year, the glowing clouds may also look like they're dancing, according to the weather service.

Shining clouds are a quite rare phenomenon, only appearing a few days in the year. If you missed it last night, there is still a chance of noctilucent clouds in the coming weeks.