What is the summer solstice?

Today marks the longest day of the year - the summer solstice. Credit: PA / Elizabeth Longbottom

Today marks the summer solstice, an event which has been celebrated for thousands of years to mark the longest day of the year and shortest night.

The word "solstice" comes from the Latin word, "solstitium", which means the "sun stands still".

In the northern hemisphere, the summer solstice marks the start of astronomical summer - the point at which the northern hemisphere is pointing directly towards the sun.

Parts of the British Isles are set to have more than 16 hours of daylight today, with the sun rising at around 5am and not setting until after 9pm.

Thousands of people gathered at Stonehenge in Wiltshire to celebrate the summer solstice in 2023. Credit: PA

Whilst most people think of the summer solstice as the day, it is in fact a moment of time - precisely 3:57pm on Wednesday 21 June.

This is the exact point at which the northern hemisphere is most exposed towards the sun, leading to long hours of daylight.

After that, the northern hemisphere will slowly start tipping back the other way meaning by the end of the week, sunrises will gradually start to get later.

Astronomical seasons date back to Roman times and are worked out by the earth's position in orbit around the sun.

Here, the seasons are marked by changes in the intensity of sunlight that reaches the earth’s surface.

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