summer solstice
Revellers celebrate the summer solstice on Salisbury Plain in southern England June 21, 2014. Stonehenge is a celebrated venue of festivities during the summer solstice - the longest day of the year in the northern hemisphere.Reuters

Countries in the northern hemisphere will see the longest day of the year this Sunday, 21 June, which is marked as summer solstice. 

The summer solstice is said to be the beginning of summer in the northern hemisphere, while some experts suggest that it actually marks the midpoint of summer.

What is Summer Solstice?

On summer solstice, daylight can stretch up to 16 hours or more in the northern hemisphere due to a phenomenon wherein the Earth's axial tilt is towards the sun.

This results in the sun rising in the north of east (instead of east) and setting in the north of west (instead of west) and thus, taking a longer route in the sky.

The sun stays in the sky for longer than usual, bringing more daylight hours. 

The term 'solstice' is derived from the Latin word 'solstitium', which translates to "the sun standing still".

The sun appears to 'stop' in the sky at the solstice. It essentially means that the sun stops moving northward after reaching the Tropic of Cancer and its journey begins southward. 

In the southern hemisphere, the summer solstice falls on 22 December. 

Summer solstice will begin in the northern hemisphere at 16:38 UTC (Coordinated Universal Times) on 21 June, 2015. 

Interesting Facts about Summer Solstice 2015

  • On 21 June, your shadow at noon will be the shortest if you are in the northern hemisphere, according to EarthSky.org
  • The summer solstice day will also be warmer, as the sunrays fall on Earth at a sharper, direct angle.
  • While summer solstice in the northern hemisphere brings the longest day of the year, in the southern hemisphere the same day is the shortest, marked as winter solstice.
  • The summer solstice brings thousands of visitors to the Stonehenge monument in England each year to observe a spectacular sight.
    Standing inside the Stonehenge monument on the summer solstice, while facing north-east the sun can be seen rising above the Heel Stone, according to EarthSky.org.
  • The summer solstice also has religious significance. For Christians, the day also marks the birth of St. John the Baptist. Several Pagan rituals are also held on this day, usually with bonfires. 
  • In New York, many people gather at Times Square to perform yoga right from sunrise to sunset, according to The Huffington Post. What makes this summer solstice extra special for yoga enthusiasts, is that it is also the first ever International Day of Yoga on 21 June. 
  • This 21 June is also Father's Day, which gives fathers around the world extra day hours to indulge in their special day of the year.