NSW has been slammed with high winds and torrential rain, with eight flood evacuation orders being issued for the NSW mid-north coast.

People in Kempsey were told by the State Emergency Service to evacuate by midnight as there was major flooding possible along the Macleay River.

Evacuation orders have been issued for low lying areas of Kempsey, Macksville, Port Macquarie, the lower Macleay, Wauchope and Rawdon Island, Taree and Wingham.

Kempsey recorded a shocking 173mm of rain between 9 am Sunday to 4 am on Monday, with no sign of slowing.

More evacuation orders are expected to be declared today, with emergency workers conducting more than 150 flood rescues and have responded to more than 1,500 calls for help.

The total for the weekend has been higher than 10,000 calls for help or flood rescue.

Emergency Services Minister David Elliot said that the NSW government was expected to be able to confirm whether the Australian Defence Force would move in to support the SES.

“That will include logistics, obviously, assistance with making sure we make safe our communities,” he said.

200 schools have also been closed today with the wild wet weather not making it safe for students to attend.

“Safety has to come first,” Education Minister Sarah Mitchell told 7NEWS.

Decisions will be made hourly on further closures.

Premier Gladys Berejiklian has urged people to be safe in the wild weather.

“It’s the sustained rainfall, the fact that weather event has settled in, it’s not moving,” she told reporters during an emergency press conference on Sunday.

“We cannot underestimate the ferocity of these weather conditions. We have gone from extreme bushfire to extreme flood.”

Bureau of Meteorology flood operations manager Justin Robinson said that this will be one of the “biggest floods we will see for a very long time”.

“Just to give you some context around that, it is bigger than the February 2020 flood. It is bigger than the 1988 flood. It is bigger than the 1990 flood and is bigger than the 1964 flood.”