While the downpour had eased on Tuesday, Port residents were being warned that more rain was on the way.

The NSW Bureau of Meteorology on Tuesday had forecast a high chance for further rain on Wednesday and Thursday along with possible thunderstorms, light winds and a drop in temperature overnight.

The sun is forecast to briefly return on Friday, leading into a cloudy weekend with some showers.

According to the BOM, Williamtown recorded 48.4mm of rain in just one hour to 8am on Monday. By the end of the day, 128mm of rain had fallen in Williamtown.

Unable to cope with the huge volume of water, Medowie Road near the Nelson Bay Road roundabout closest to the RAAF base was briefly closed on Monday afternoon.

Newcastle Airport also closed its airfield due to flooding on Monday. Flights returned as scheduled on Tuesday. Streets around Medowie were also overrun with water.

Residents took to social media to post videos and photos of water running like rivers through properties and over roads in Boyd Boulevard, Kirrang Drive, South Street and Sir Henry Parkes Avenue near Federation Drive.

Port Stephens SES received 50 requests for assistance throughout Monday for trees over roads, roof leaks and collapses and other property damage.

"One of these jobs was to a childcare centre with 120 children on site with water entering the centre," Alysha Springett from the Raymond Terrace-based SES unit said.

"The SES operators checked the site ensuring that the children and staff were safe. SES in conjunction with very safety conscious staff members decided that with the deterioration of weather conditions that the appropriate course of action was to arrange parents to collect the children.

"It was fantastic to see that the centre had developed and implemented an effective emergency response plan and contacted SES for assistance early."

Ms Springett thanked SES volunteers who took time off work on Monday to support the community.

For emergency help in floods and storms phone the SES on 132 500.