<P> Calendar - based reckoning defines the seasons in absolute rather than relative terms . Accordingly, if floral activity is regularly observed during the coolest quarter of the year in a particular area, it is still considered winter despite the traditional association of flowers with spring and summer . Additionally, the seasons are considered to change on the same dates everywhere that uses a particular calendar method regardless of variations in climate from one area to another . Most calendar - based methods use a four - season model to identify the warmest and coldest seasons, which are separated by two intermediate seasons . </P> <P> Meteorological seasons are reckoned by temperature, with summer being the hottest quarter of the year and winter the coldest quarter of the year . In 1780 the Societas Meteorologica Palatina (which became defunct in 1795), an early international organization for meteorology, defined seasons as groupings of three whole months as identified by the Gregorian calendar . Ever since, professional meteorologists all over the world have used this definition . Therefore, for temperate areas in the northern hemisphere, spring begins on 1 March, summer on 1 June, autumn on 1 September, and winter on 1 December . For the southern hemisphere temperate zone, spring begins on 1 September, summer on 1 December, autumn on 1 March, and winter on 1 June . In Australasia the meteorological terms for seasons apply to the temperate zone that occupies all of New Zealand, New South Wales, Victoria, Tasmania, the south - eastern corner of South Australia and the south - west of Western Australia, and the south east Queensland areas south of Brisbane . </P> <Table> <Tr> <Th_colspan="4"> Australasian seasons </Th> </Tr> <Tr> <Th> Season </Th> <Th> Start date </Th> <Th> End date </Th> </Tr> <Tr> <Td> Summer </Td> <Td> 1 December </Td> <Td> 28 February </Td> </Tr> <Tr> <Td> Autumn </Td> <Td> 1 March </Td> <Td> 31 May </Td> </Tr> <Tr> <Td> Winter </Td> <Td> 1 June </Td> <Td> 31 August </Td> </Tr> <Tr> <Td> Spring </Td> <Td> 1 September </Td> <Td> 30 November </Td> </Tr> </Table> <Tr> <Th_colspan="4"> Australasian seasons </Th> </Tr>

When does summer end in the southern hemisphere
find me the text answering this question