The official start of summer kicks off in the Northern Hemisphere today (June 21), marking the longest day of the year — which also happens to coincide with Father’s Day.
The June solstice will occur at 11:32 p.m. EDT (0332 June 21 GMT), when the sun reaches the point at which it is farthest north of the celestial equator. Reaching its highest and northernmost point in the sky, the sun must travel its longest path, meaning it will take longer to rise and to set, which is why today marks the longest day — or longest period of sunlight hours — and shortest night.
In addition, the summer solstice occurs at the moment the northern half of Earth is tilted toward the sun, meaning the Northern Hemisphere receives sunlight at the most direct angle of the year.
At this time, the sun will appear directly overhead for a point on the Tropic of Cancer (latitude 23.5 degrees north) in the central Pacific Ocean, 817 miles (1,314 kilometers) east-northeast from Honolulu.
Conversely, the June solstice marks the beginning of winter in the Southern Hemisphere, when the sun is at its lowest point in the sky and the southern half of Earth is tilted away from the sun.
Source: El Informador
