The Longest Day of the Year - June 21

 

Today is thelongest day of the year as June 21 marks the summer solstice

 It’s the day when there are the most hours of sunlight

The summer solstice occurs when the tilt of a planet's semi-axis, in either the northern or the southern hemisphere, is most inclined toward the star that it orbits. Earth's maximum axial tilt toward the Sun is 23° 26'. This happens twice each year, at which times the Sun reaches its highest position in the sky as seen from the north or the south pole.

As the Earth takes its yearlong trip and spring turns to summer, the North Pole heads more and more toward the sun until a date between June 20 and 22, when it reaches its maximum before starting to point away again.

That maximum is the summer solstice, which this year falls on June 21. Today, the sun will be directly over the Tropic of Cancer, which is at 23.5 degrees North latitude.