The Sumerians are thought to have formed the first human civilization in world history. They lived in southern Mesopotamia, between the Tigris and Euphrates Rivers in the Middle East. Cradle of Civilization. Many historians think that cities and towns were first formed in Sumer around 5000 BC.
At noon, on March 21 and September 23rd are the vernal and autumnal equinoxes. The sun is directly overhead at the equator at these times. On June 22nd is the summer solstice, in the Northern Hemisphere. The sun is at the 23.5 degrees Northern latitude.
Quick Answer. The longest day of the year for people in the Northern Hemisphere is on June 21. This marks the summer solstice when the sun is exactly overhead on the Tropic of Cancer at 23.5 degrees latitude. Continue Reading.