The end of summer foretells of an unwelcome Game of Groans

Winter is coming' is an oft-used phrase in the TV series Game of Thrones as both a portent of doom and an observation on the weather.

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It foretells, among other catastrophes, the arrival of the White Walkers and their undead army. It also reminds those in Castle Black to turn the thermostat up a few degrees.

The influential character Jon Snow is often seen telling his acolytes, while staring moodily into the middle distance: 'Eeeh, it's a bit nippy isn't it?' before hastily buttoning up his parka.

Followers of this classic TV show may be able to pick holes in my Game of Thrones knowledge, but then I haven't watched it.