Winter is one of the four seasons of temperate zones. Astronomically, it begins with the winter solstice (around 21 December in the Northern hemisphere, and 21 June in the Southern hemisphere), and ends with the spring equinox (around 21 March in the Northern hemisphere and 21 September in the Southern hemisphere). However, sometimes it is counted instead as the whole months of June, July and August in the Southern hemisphere and December, January and February in the Northern hemisphere.
Wintering is a term used to refer to seasonal climate-related migrations, such as those of migratory birds or Monarch butterflies. By extension, it is also refers to seasonal agricultural practices, such as transferring beehives to warmer locations.