The Equator is the line at 0 degrees latitude that circles Earth.
It divides the planet into the Northern Hemisphere and Southern Hemisphere. Unlike lines of longitude, which converge at the poles, the Equator is a great circle: its plane passes through Earth’s center. It is about 40,075 kilometers long, though the exact distance depends on whether it is measured around Earth’s equatorial bulge.
Places near the Equator generally experience little seasonal variation in daylight length. Day and night are close to equal throughout the year, while the Sun can appear directly overhead at noon on dates near the equinoxes. Temperature, however, varies with elevation, clouds, rainfall, and local geography, so not every equatorial location is uniformly hot.
The Equator passes through land or territorial waters of several countries, including Ecuador, Colombia, Brazil, São Tomé and Príncipe, Gabon, Republic of the Congo, Democratic Republic of the Congo, Uganda, Kenya, Somalia, Indonesia, and Kiribati. The name Ecuador comes from the Spanish word for “equator.”