Topography
Sydney's urban area is in a coastal basin, which is bordered by the Tasman Sea to the east, the Blue Mountains to the west, the Hawkesbury River to the north and the Royal National Park to the south. It lies on a submergent coastline, where the ocean level has risen to flood deep river valleys (ria) carved in the Hawkesbury sandstone. Port Jackson, better known as Sydney Harbour,
Climate[edit]
Sydney has a temperate climate with warm summers and mild winters, with rainfall spread throughout the year. The warmest month is January, with an average air temperature range at Observatory Hill have temperatures of more than 30 °C.
In winter, temperatures rarely drop below 5 °C in coastal areas. The coldest month is July, with an average range of 8.0–16.3 °C
The city is not affected by cyclones, although remnants of ex-cyclones do affect the city. The El Niño–Southern Oscillation plays an important role in determining Sydney's weather patterns