AROUND this time of the year, every year, skywatchers start to look out for silvery blue-grey clouds above the northern horizon after midnight, writes STUART ATKINSON. These are noctilucent clouds - or NLC for short - and they are only seen between the end of May and the start of August, during NLC season. Every year as May draws to a close we wonder when the season will begin and we'll catch our first glimpse of these beautiful clouds.

I'm happy to report that the 2019 NLC season has begun, and I know that for a fact because I've seen my first display of the year. They were only faint, and low down, and looked much more impressive on my camera than they did to my eye, but they were there, and bigger and brighter displays will surely follow in the days and weeks ahead. So, what are NLC and what do you need to do to see them?

Noctilucent means 'night shining,' so these are clouds that shine in the night instead of looking dark. They shine because they are very high in the atmosphere and bathed in sunlight long after it's dark on the ground. To see them you need to be outside looking north after midnight. NLC appear as wisps, tendrils and swirls of eerie-looking silvery and electric blue. Some displays are very small and faint, and barely clear the horizon, but others can be strikingly bright, covering the sky from west to east - a sight you'll never forget.

So, any clear night from now until August make sure you look to the north after midnight. You might see something beautiful.