That was 2017-06-20, that was. A beautiful blue sky with white fluffy wispy cirrus cloud catching the setting sun…

…followed by a noctilucent cloud display around 1am:

NLCs are the highest-flying clouds, occurring at altitudes up to 80km where the next highest type (cumulonimbus) only reaches 12km and most are lower still. Most typically they resemble a fine silver filigree of ice-cold pale blue, although more complex forms have been seen. First maybe-seen in 1885, they only really came to prominence since the 1980s, as a canary for changes in the upper atmosphere linked to climate change.

As I stood and watched the display, a patch of silver mist formed over Strathearn and made its way west along the A85 toward Crieff, so I made a little timelapse video – 17 minutes’ data compressed into 1: