The city was hit by a hail storm around 2.30pm, with reports some of the hail stones were the size of golf balls.

The storm front loomed quickly, and lasted for around five minutes. The rain continued on and off then for the rest of the afternoon as many tucked into their leftover Christmas ham.

Much of the hail remained on the ground well after the storm had left. The temperature maxed out at 25.7 degrees just before 2pm, before dropping dramatically when the storm front rolled into Orange. The temperature dropped almost 10 degrees when the storm hit and the hail rocketed out of the sky.

The city's main weather station at the Orange Airport indicates around 4.6mm of rain fell on Christmas day.

NSW SES Orange City Unit unit commander Rob Stevens said his team responded to about 40 incidents as soon as the storm hit.

Since then, he's had four teams continuously going from job to job to help clear up the mess.

He said there has been trees on houses, trees blocking roads and plenty of smashed roof tiles to repair following the storm.

"Certainly some of the larger hail stones were golf-ball sized or larger. I'd say most were about a large marble to ping pong ball size. But generally we've probably seen the largest hail stone to fall in Orange in around a decade," Mr Stevens said.

He said the main areas of Orange impacted were in the city's southern areas, near Racecourse Road and Sunny South Crescent. He the likes of Pinnacle Road, Cargo Road and Canobolas Road were at times impacted by trees over the road.

No one was seriously injured by the storm, Mr Stevens said. Although he warned people the stones that fell were large enough to cause significant injury.

"Certainly the damage we saw on vehicles ... had that have had hit people it might have sent them to hospital or worse," he said.

Mr Stevens said the weather has been very volatile and unpredictable this Christmas. He urged people to remain indoors should more storms hit during summer.

"And if you know a hail storm is approaching, little things like tossing blanket over cars might help avoid some of the damage," he said.

State-wide, more than 1100 NSW State Emergency Service (SES) volunteers have worked tirelessly throughout Christmas Eve and Christmas Day, responding to a series of severe weather events that have affected many communities.

On Christmas Day, NSW SES volunteers responded to 312 incidents, which is in addition to the 492 incidents that were recorded on Christmas Eve.

Residents at Grenfell were treated to a white Christmas, as hail blanketed the town shortly after midday. NSW SES Assistant Commissioner Sean Kearns said 41 incidents were reported in the small town.

"There was damage to properties including broken skylights, parts of roofs, broken windows, and damaged vehicles," Assistant Commissioner Kearns said.

"This kept local SES crews and two teams from Forbes busy throughout the day".

Meanwhile, intense heavy rainfall was received in southeastern parts of NSW. At Eurobodalla, 156mm of rain was received in three hours, resulting in flooding of local roads, and inundation of some properties.

Volatile weather conditions are expected to continue for the next 24-48 hours.

Assistant Commissioner Kearns said the NSW SES remains on high alert and is prepared to respond promptly to emerging situations.

"We're particularly aware at this time of the year a lot of people undertake Christmas travel plans to be with their friends and family, however, we ask the public to be mindful of the ongoing severe weather," he said.

"Roads may be hazardous due to flash flooding, damage from recent rainfall and fallen debris, and reduced visibility. Travellers are strongly advised to stay informed about current conditions, exercise caution, and consider delaying travel if conditions worsen."

For emergency help in floods and storms, call the NSW SES on 132 500. In life threatening situations, call Triple Zero (000) immediately.