Northern Hemisphere

The Northern Hemisphere of Earth is the half that is north of the equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's North pole.

Due to the Earth's axial tilt, winter in the Northern Hemisphere lasts from the winter solstice (typically December 21 UTC) to the March Equinox (typically March 20 UTC), while summer lasts from the summer solstice (typically June 21 UTC) through to the autumnal equinox (typically September 23 UTC). The dates vary each year due to the difference between the calendar year and the astronomical year.