The summer solstice is happening in the Northern Hemisphere Tuesday, marking the longest day of the year and the first day of the new season.
The event officially begins at 5:13 a.m. on the U.S. East Coast, according to the National Weather Service.
A solstice occurs when "Earth arrives at the point in its orbit where the North Pole is at its maximum tilt [about 23.5 degrees] toward the Sun, resulting in the longest day and shortest night of the calendar year," the agency said.
During the solstice, the sun is at its highest point--over the Tropic of Cancer--and there are the most hours of daylight and least hours of darkness of any day in the year.
Solstices happen every June and December, occurring at the same time around the world and marking the year's longest and shortest days.
While Tuesday marks the longest day of the year in the Northern Hemisphere, it is the shortest day of the year in the Southern Hemisphere. And while summer officially begins in the Northern Hemisphere, winter gets underway in countries that are south of the Equator, such as Australia and Brazil.
For various places around the world, the summer solstice starts at:
- 2:13 a.m. in Los Angeles
- 3:13 a.m. in Denver
- 4:13 a.m. in New Orleans
- 10:13 a.m. in London
- 11:13 a.m. in Cairo
- 12:13 p.m. in Jerusalem
- 1:13 p.m. in Dubai
- 5:13 p.m. in Manila, Philippines
- 6:13 p.m. in Tokyo
