NSW is facing danger on multiple fronts with rain set to worsen, threatening floods and erosion, as conditions deteriorate earlier than expected

Areas stretching from Newcastle to the South Coast and as far inland as Oberon are in the danger zone, including western Sydney's flood-prone Hawkesbury-Nepean area.

The Bureau of Meteorology has a severe weather warning in place for heavy rain leading to flash flooding, winds up to 90km/h and damaging surf along the coast.