Winter solstice: 'Summer is on its way'
The winter solstice is the shortest day of the year.
While it is the winter solstice in one hemisphere it is the summer solstice in the other hemisphere.
In the UK, the winter solstice is a little after 11pm on 21 December this year. However, the date of the solstice depends on where you are on the planet.
BBC Weather's John Hammond explains.