The 134-hectare blaze is seven kilometres from the closest suburbs -  Kambah, Greenway, Bonython and Gordon - and remains at a "watch and act" alert.  No evacuations have been ordered and no property was under threat.

Firefighters have been focused on property protection, unable to attack the blaze at Pierces Creek directly due to its erratic nature, with tree-top flames even in the early hours of the morning.

The ACT Emergency Services Agency says the watch and act alert means that "conditions are changeable and residents should consider how you should protect you and your family if the fire were to spread''.

It has warned embers could fly into the suburbs of Canberra, saying the risk to Tuggeranong was "pretty evident'' and urged residents to get ready now.

At 6am on Friday and throughout much of the day, the Pierces Creek fire was 8km from the nearest suburbs, but had closed in to being 7km away by 4pm.

Agency personnel are doorknocking between 400 and 700 homes from Kambah to Gordon along the urban fringe, ie those homes closest to bushland. That includes homes also in Greenway and Bonython.

It says no evacuations have been ordered for residents, horses or other animals.

"There is currently no threat to property,'' the agency says.

The ACT Education Department denied rumours on Facebook that Tuggeranong public schools were being evacuated and instead said they were operating as usual.

But the Emergency Services Agency later advised, "ACT Schools should refer members of the public to Access Canberra on 13 22 81 or www.accesscanberra.act.gov.au for information on temporary school closures.''

A map of the fire is available at www.esa.act.gov.au.

The agency says the doorknocking in Tuggeranong is "an education activity''.

"Emergency personnel are conducting this exercise to educate people about what the fire threat alert levels mean," it says.

Residents can download the bushfire survival plan here.

The fire is burning erratically and is heading in a southeasterly direction in steep terrain.

Emergency Services Commissioner Dominic Lane said increasing winds would make it difficult for firefighters battling the Pierces Creek blaze on Friday.

Commissioner Lane told ABC Radio "the risk is pretty evident" to Tuggeranong residents.

"If you live in the Tuggeranong Valley and look to the north-west you will no doubt see that fire," he said.

"It is heading towards the Tuggeranong Valley based on the weather conditions. And while we don't want people to panic, we do need people to start planning."

Commissioner Lane later told a lunchtime press conference that due to the extremely dry conditions, the firefighters were facing conditions similar to the 2003 firestorm when four people died and close to 500 homes were destroyed. He feared people had become complacent in the ensuing nearly 16 years since the firestorm, but now was the time to act.

"So this is a strong reminder to our community, to the ACT citizens – now’s the time to get ready,'' he said.

"Download your bushfire survival plan from the ESA website, take notice of the information, keep up-to-date with the ESA website in terms of warnings and alerts and download the Fires Near Me app.

"This fire remains uncontrolled. We are very fortunate to have our firefighters on
scene from Parks and Conservation, the Rural Fire Service, and ACT Fire and Rescue as well as support
from our interstate colleagues in NSW to protect the local area.

"But we remain concerned in these extremely dry conditions there’s still a chance that this fire could be subjected to spotting activity and spot over the mountains to east and into the suburbs of Canberra.''

Commissioner Lane said the fire was uncontrolled and not being attacked directly.

"This fire is being fought during the day in property protection mode. We are not in a position to
directly attack this fire because the fire behaviour is just too erratic,'' he said.

"We saw overnight even at two o'clock in the morning, flames at tree-top height. Firefighters tried bravely to get in and contain the fire. It was just too dangerous.

"Those conditions still exist down there at the moment so our main strategy is around property protection and preparing our community

The ACT Government has closed Kambah Pool and Kambah Pool Road. Camp Cottermouth is also closed until further notice.

On direction from the Emergency Services Agency, the Australian National University has closed its Mount Stromlo site to visitors "and are working closely with those remaining onsite''.

"At 11.45am today, emergency services started door-knocking residential areas in Kambah and Gordon along the urban corridor, providing advice on what to undertake in the event fires move into the Tuggeranong area,'' a statement from the university read.

"Any students or their immediate families that reside in those areas, are welcome to return home and make any necessary preparations.

"Students whose examinations may be affected may make arrangements for deferred assessments through: http://www.anu.edu.au/students/program-administration/assessments-exams/deferred-examinations.''

The fire started from a burnt-out car. Its focus has been at Pierces Creek, a former forestry settlement, that was also burnt to the ground in the 2003 bushfires.

More than 20 crews from ACT Fire & Rescue and ACT Rural Fire Service are on site. Throughout the day five helicopters have conducted water bombing operations to assist and the LAT (Large Aeroplane Tanker) has dropped retardant over the site.

The Bureau of Meteorology has issued a severe thunderstorm warning for the ACT and surrounding region Friday afternoon with the potential for damaging winds over the next several hours. They also advise that the haze over Canberra is not smoke but dust from inland NSW. It is likely to get thicker throughout the evening.

The Health Directorate advises that people with asthma, other chronic respiratory and/or chronic cardiac diseases should not perform vigorous exercise and should stay inside if affected by the dust.
People with asthma in particular should continue their medication and consult their general practitioner if they have any difficulties.