State Emergency Service crews will continue the clean up this morning after a severe storm hit parts of the Hunter yesterday afternoon.

Crews worked late into the night after being called out to almost 270 jobs.

172 of those were in Port Stephens.

There was also more than 40 calls for assistance in Dungog.

SES spokeswoman Mandy Haigh says most of the damage was caused by falling trees and branches.

"We had a very very late night and the crews worked well after midnight," she said.

"The majority of it was tree damage, so trees down, broken branches, trees on houses, trees on fences, so a lot of tree work, a lot of chainsaw work."

Ms Haigh says extra crews were brought in from across the Hunter region to assist with the clean up.

"We sent crews up to Dungog to assist, we sent crews from Newcastle and Lake Macquarie to Tomaree to assist and then we sent a couple of other small crews to help in other areas in the Hunter as well.

"There was a lot of trees involved with powerlines and fortunately we had a lot of the other services out there working as well."

Ausgrid emergency crews are continuing work to restore power to about 2,500 homes and businesses around Nelson Bay, Corlette and Salamander Bay.

Lightning strikes on electrical equipment caused power supplies to shut down, while strong winds brought down trees onto powerlines, causing major damage to the electricity network.

At its peak, there were about 12,000 homes and businesses around Port Stephens and the Upper Hunter regions without power.

The main areas affected were Nelson Bay, Corlette, Soldiers Point, Salamander Bay, Lemon Tree Passage, Karuah, Scone, Aberdeen and Muswellbrook.

Ausgrid is hoping power will be restored by early afternoon to all homes.

Rainfall figures from two rain events on Friday and Sunday varied wildly across the region.

Scone received 21 millimetres while Gundy had 50, Muswellbrook had 47, Wybong 11 and Camberwell 3 millimetres.