The summer solstice is generally understood to mark the first day of summer.
Technically, it’s when the northern hemisphere of the Earth is most inclined towards the sun, and that’s why we get the most daylight of the year.
During the winter solstice, the northern hemisphere is tilted furthest away from the sun, hence fewer hours of daylight and the shortest day.
The word solstice is derived from the Latin words sol (sun) and sistere (to stand still), because the seasonal movement of the Sun’s path (as seen from Earth) momentarily comes to a stop before reversing direction.
In the northern hemisphere, the summer solstice takes place between June 20 and 22. This year it’s on Wednesday, June 21 .
The shortest day of the year is known as the winter solstice, and occurs between December 20 and 22. This year it is on Thursday, December 21.
In London, on the summer solstice, the sun will rise at 04:43 and set at 21:21.
Near Stonehenge in Salisbury, sunrise will be at 04:52 and sunset will occur at 21:26.