A few weeks either side of the summer solstice is the best time to observe ‘noctilucent’ or ‘night shining’ clouds.

These wispy collections of ice crystals are the highest clouds on Earth, located in the mesosphere up to 50 miles overhead. They’re too faint to be seen in daylight and best observed when the Sun is between -6 and -12 degrees below the horizon.

At the moment at Highland latitudes this gives you an approximate window between 11.30pm and 3am in the morning.