Summer is one of the four temperate
seasons. Astronomically, it begins with the
summer solstice (around 21 June in the
Northern hemisphere, and 21 December in the
Southern hemisphere), and ends with the
autumn equinox (around 21 September in the Northern hemisphere and 21 March in the Southern hemisphere). However, sometimes it is counted instead as the whole months of December, January and February in the Southern hemisphere and June, July and August in the Norhtern hemisphere.
See also: axial tilt
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