than other mainland Australian state capital cities in the winter. The lowest temperature on record is ?2.8 �C (27.0 �F), on 4 July 1901. However, snowfalls are rare: the most recent occurrence of sleet in the CBD was on 25 July 1986 and the most recent snowfalls in the outer eastern suburbs and Mount Dandenong were on 10 August 2005. More commonly, Melbourne experiences frosts and fog in winter.
Melbourne summers are notable for occasional days of extreme heat. This occurs when the synoptic pattern is conducive to the transportation of very hot air from central Australia over to the south east corner of the continent. The inland deserts of Australia are amongst the hottest areas on earth, particularly the inland parts of north-west Australia. Every summer, intense heat builds starting in the Pilbara district of Western Australia around October/November and spreading widely over the tropical and subtropical inland parts of the continent by January. In the summer months, the southern part of the continent straddles the westerly wind belt to the south and the subtropical high pressure ridge to the north. The intense heat buildup occurs where high pressure is highly dominant in the upper levels of the atmosphere over the tropics and subtropics of Australia in summer allowing for a huge area of stable atmospheric conditions to predominate. On occasion a strong cold front will develop in summer and bring the westerlies further north than their mean summer position. On these occasions, north-west winds will develop ahead of the cold front's passage and sometimes these can be very strong, even gale force. When this occurs the hot air from the inland is dragged right down over south east Australia, occasionally even as far as southern Tasmania. As this air mass is carried entirely over the continental land mass it remains unmodified, i.e. it does not pick up additional moisture from a body of water and retains most if not all of its heat. On these occasions, the
