Eleven homes have been lost and 12 more damaged in a fire which ripped through 3500 hectares of land at Carwoola.

Of those 11, one belonged to a senior firefighter who was out defending the homes of others. A further 45 outbuildings were destroyed and 40 were damaged. There was "quite a number" of stock lost, with a figure yet to be determined. At least 56 homes were saved by firefighting efforts, many came within inches of the fire.

The fire began on Friday, a day of total fire ban in the region. It reached emergency status and remained that way until late evening. The fire was contained on Saturday afternoon. Crews would remain on the scene to patrol the area in the coming days, as hot spots continued to smoulder.

An unexpected weather change about midday on Saturday brought welcome relief for firefighters and residents. About five millimetres of rain fell on the charred earth, which had been well alight the day prior.

But firefighters were warning residents to remain vigilant as storms sweeping across the state saw lightning strikes spark more than 100 fires.

Having worked throughout the night to protect properties from the fire burning at Captains Flat Road between Carwoola and Hoskinstown, firefighters said they were monitoring lightning strikes closely.

NSW RFS confirmed two firefighters had also been injured while fighting the blaze and were taken to the Canberra Hospital.

A spokeswoman for ACT Health said one of the firefighters was released from hospital, while the other remained in a stable condition on Saturday.

About 200 firefighters, 50 fire trucks and at least 10 aircraft worked to establish containment lines on Friday, but the blaze had burnt 2700 hectares by 7pm.

The ACT Emergency Services Agency provided an initial boost of firefighting resources, on request from NSW, sending in 120 firefighters and support personnel, plus both of the capital's water bombing helicopters. On Saturday, a further six ACT RFS units were deployed to help with the control and mopping up efforts.

NSW RFS deputy commissioner Rob Rogers praised the actions of volunteers crews on the ground, saying the situation could have been much worse.

"The fire moved frighteningly quickly and the remarkable thing is how quickly that fire developed," he said.

"Anybody that looks at that landscape can see how quickly that fire moved through that area and how very lucky we are that there wasn't loss of life or more property."

He said the RFS was "very concerned" about the potential of the fire.

"We threw everything we had at it," he said.

"It's as good an outcome as we could have got, but our sympathy goes out to those who have lost their homes."