Climate of New South Wales

New South Wales is entirely in the temperate zone. The climate is generally mild, equable and mostly free from extremes of heat and cold, but very high temperatures occur in the northwest and very cold temperatures on the Southern Tablelands. The Great Dividing Range, running approximately north to south in the east of New South Wales, has a large impact on the climate, creating four distinct climate zones; the coastal strip, the highlands, the Western Slopes and the flatter country to the west.

The climate of the coastal strip is influenced by the warm waters of the Tasman Sea, which in general keep the region free from extremes of temperature and provide moisture to increase rainfall, the annual median of which ranges from about 750 mm in the south to 2000 mm in the north.

The mountains of the Great Divide attain a maximum height of 2228 metres at Mt. Kosciuszko, and there are several peaks in excess of 1500 metres, extending up to northern NSW. Traveling from east to west across the range, the elevation abruptly increases away from the coastal plain, and then west of the divide it gradually descends onto the Western Plains. Consequently winter snowfalls are experienced over what are aptly called the Tableland regions.

On the Western Slopes the rainfall gradually decreases, together with the frequency of winter snowfalls. Average maximum temperatures gradually increase as height above sea level decreases.

Further to the west the land slowly flattens out to the dry inland plains, notable for cold nights. It is in the far northwest where the hottest temperatures in the State most commonly occur during summer, and where the annual mean rainfall drops below 200 mm.

The way in which the climate changes across the State is reflected by marked changes in vegetation, which ranges from the subtropical rainforests of the northeast to the fragile alpine heathlands in the southern Alps, through the dry forests and undulating pasturelands of the midwest to the dry plains of the northwest.

Outdoor activities also vary significantly across the State. Mild winters along the North Coast favour beach activities whilst at the other extreme the snow fields of the southern Alps become a winter playground for skiers.

Perhaps the most basic need of human settlement is water; early Australian history has many examples of new settlements that foundered due to lack of adequate water supplies. Settlement to the west of the Great Dividing Range was made more difficult by a lack of a reliable water supply. Settlement onto the open plains that flourished during years of good rainfall foundered during drought periods, In more recent times, irrigation schemes have been developed to harness some of the heavy rainfall and snowmelt from the Tablelands and control its release westwards.