A 13-year-old girl has been arrested for allegedly lighting several fires in Adelaide's south, a day after 11 properties were damaged during catastrophic fire conditions in the state.

Police were called to Burgess Dr at Noarlunga Downs just before 11pm on Thursday after receiving a report that someone was starting fires in the area.

Two more fires were started in nearby Goldsmith Dr and Grey Box Ave.

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Police used a helicopter and a police dog to track down the suspect, who was seen running from the area.

An hour later, another fire was reported on Oslo Ct at Hackham West.

The teenage girl was arrested at a house in the same suburb and was charged with causing a bushfire.

No property was damaged in the fires that burnt through leaves and vegetation.

The arrest came as firefighters continued to battle dozens of blazes burning across the state.

At the peak of Wednesday's catastrophic fire conditions, 69 fires were burning as the temperature hit 40 degrees Celsius and strong winds fanned flames.

Yorketown on the Lower Yorke Peninsula was the worst hit with 11 properties damaged after a power network fault sparked a fire.