On Monday, March 20, 2017, we’ll be welcoming spring and saying farewell to the 2016-2017 Winter.

Spring officially arrives at 6:29am ET.

The timing of the four seasons is determined by shifting sunlight, which on its own is determined by how our planet orbits the Sun and the tilt of its axis. Half-way between winter and summer, spring will see days getting longer and temperatures getting warmer throughout the northern hemisphere (while the days will be getting colder in the southern hemisphere.)

To simplify things, meteorologists use dates other than the equinox to determine the start/end dates of weather seasons. The first day of meteorological spring arrived March 1 and ends May 31.