When is this year's Summer Solstice?

When is the summer solstice in 2024?

In 2024 the summer solstice will occur on Thursday 20 June at 21.51 BST (20.51 GMT). 

What is the summer solstice?

The summer solstice occurs in June in the Northern Hemisphere and marks midsummer: the 'longest day' and 'shortest night' of the year.

On this day, the number of hours of daylight are at their maximum, while the number of hours of night are at their minimum.

However, while most people consider the summer solstice to be a day, it is in reality an exact moment in time that falls upon that day. This moment comes when whichever hemisphere you're in is most tilted towards the Sun.

Astronomical definition of the solstice

Our Earth rotates on its axis once each day, producing the cycle of day and night.

At the same time, the Earth moves around the Sun on its orbit over the course of a year.

However, the axis of rotation of the Earth is not lined up with the axis of motion around the Sun. Instead, it is tilted slightly at 23.44°.

This tilt means that during one half of the year the North side of the Earth is tilted slightly towards the Sun and the South is tilted away. For the other half of the year the reverse is true.

(taken from the Royal Museums Greenwich www.rmg.co.uk)