Police believe a fire in grassland in Gordon was deliberately lit.
The fire was lit on a total fire ban and while the ACT is in a State of alert given the weather conditions and fires burning in the region.
"About 12.30pm ACT Fire and Rescue attended a grassland area near Woodcock Drive and Preddey Way and extinguished a small grass fire," police said in a statement.
"Following analysis of the scene, police and fire investigators believe the fire was deliberately lit."
They are looking for anyone who knows anything about the fire or who might have CCTV footage or dash cam footage from around the area. Anyone who can help the investigation was asked to contact Crime Stoppers on 1800 333 000, or via the Crime Stoppers ACT website and quote 6483281.
Police said they were patrolling parts of the territory during total fire bans to deter and detect any suspicious activity or anti-social behaviour.
They asked anyone who noticed suspicious activity to contact police on 131444 or 000 in an emergency.
While Friday's conditions heighten the risk for new fires to ignite within the ACT, the immediate priority for local firefighting crews will be helping their NSW counterparts in tackling blazes burning through the Snowy Mountains region.
ACT Emergency Services Agency commissioner Georgeina Whelan said if a fire did break out in the ACT, crews deployed to NSW could be called back at short notice.
"We would not put out anything that we could not withdraw straight away," she said.
"I will not leave the ACT exposed. Our community is concerned is about what is happening in NSW, so we are contributing to that [firefighting effort].
"Equally, they are concerned about what will happen in our borders, so we are balancing that out as well."
In anticipation of another spell of extreme weather in the ACT, Chief Minister Andrew Barr on Thursday declared the territory would remain in a "state of alert" for the "foreseeable future". The declaration puts Canberrans on notice to prepare for the possibility of a bushfire emergency.
"As we have said, on our worst bushfire day, we can't have firefighters protecting every single home," Mr Barr said.
"Again, we ask and stress that if you haven't downloaded your bushfire survival plan and filled it out, please do so now."
Temperatures in Canberra are expected to cool over the weekend, with the Bureau of Meteorology forecasting a top of 28 on Saturday and 24 on Sunday.