When is summer solstice? What is longest day of year?
This year the summer solstice, or midsummer, is on Thursday, June 21.
The summer solstice is also the same date as the longest day of the year and it marks the moment the sun reaches its highest point in the sky in the northern hemisphere.
The astronomical event occurs each year when the Earth achieves its maximum tilt at 23.44 degrees on its rotational axis towards the sun.
Every year the date varies because the earth’s elliptical orbit around the sun changes slightly in speed depending on the gravitational pull of the planets and moons.
This means the summer solstice takes place about six hours later every single year.
During the winter solstice in December, the opposite happens with the longest night of the year and the least amount of daylight.
On June 21, 2018, the sun will rise at 4.43am and set at 9.21pm.
What is the meteorological summer?
Many people will also be aware that the start of summer has another official date.
Meteorologists use the meteorological summer, which begins on June 1 and runs until August 31, to predict its weather forecasts.
The UK’s Met Office divides the year into four distinct seasons based on the Gregorian calendar.
They are spring (March, April, May), summer (June, July, August), autumn (September, October, November) and winter (December, January, February).
How do people celebrate the summer solstice?
Midsummer festivals are usually held in many countries to celebrate the longest day of the year.
In the UK, thousands of people flock to Stonehenge in a popular pagan ritual to watch the sunrise towards the north-east past the site’s Heel Stone.
