what makes june 21st the longest day of the year?

Answer 1

It's the longest day of the year if you're in the northern hemisphere. The reason is because the tilt of the earth's axis and the position of the earth relative to the sun make it so June 21 is the date when sun covers the biggest portion of the northern hemisphere at one time. If you were in the southern hemisphere, today would the the shortest day of the year.

Answer 2

On or around June 21 each year, the rays of the sun will be perpendicular to the Tropic of Cancer at 23°30' North latitude. This day is the summer solstice in the Northern Hemisphere.
On this day, the earth's "circle of illumination" will be from the Arctic Circle on the far side of the earth (in relation to the sun) to the Antarctic Circle on the near side of the earth. The equator receives twelve hours of daylight, there's 24 hours of daylight at the North Pole and areas north of 66°30' N, and there's 24 hours of darkness at the South Pole and areas south of 66°30' S.

June 20-21 is start of summer in the Northern Hemisphere but simultaneously the start of winter in the Southern Hemisphere. It's also the longest day of sunlight for places in the Northern Hemisphere and the shortest day for cities south of the equator.

Answer 3

It's the longest day of the year because the tropic of capricorn is getting direct sunlight. That causes the sun to reach a higher point in the sky which makes it light outside for longer. It is the shortest day of the year for the southern hemisphere and vice versa on 12/21.

Answer 4

Its only the longest for the northern hemisphere.
It is the longest because of the amount of time from sunrise to sunset is the longer than any other in the year.

EDIT:
Same as 21st of December is the shortest day because it has the shortest time from sunrise to sunset. (Included this since the question was in an answer.)

Answer 5

It has to do with the tilt of the earth relative to the sun. When the North Pole is tilted at its maximum extent toward the sun, the days are longer in the northern hemisphere. When it's at the point that it's tilted furthers from the sun, then the days are shortest. And of course, the reverse is true for the southern hemisphere - don't want to forget the folks down under! :-)

Answer 6

The day is still 24 hours just more daylight. Look up position of the earth in relationship to the sun.

Answer 7

North Pole is at max tilt toward sun on June 21.

Answer 8

What makes December 21st the shortest day of the year?

Answer 9

the earth's axis is it's farthest facing towards the sun on june 21st which makes the daylight last alot longer.

Answer 10

The summer solstice