Saturday nearly reached a balmy 19 degrees - the mercury stopping just short at 18.9 degrees, about 6 degrees above average for Canberra in August.

While that was an ''outstanding'' day statistically, it was nowhere near the August record.

''It's not some kind of extraordinary level,'' the Bureau of Meteorology duty forecaster told Fairfax Media. ''The highest temperature in Canberra in August was 24 degrees - on 13 August, 1982.''

Nevertheless, after a warmer-than-average June, and a record-breaking July, Canberra is likely to record one of its warmest winters ever.

Sunday morning saw some thick patches of fog, which prompted ACT police to issue a warning via Twitter for drivers to ''make sure your lights are on and drive carefully''.

After the fog lifted, the temperature reached a sunny 15.8 degrees.

While there is a south-westerly change developing and a chain of cold fronts coming, temperatures still aren't expected to drop much this week, with mild overnight temperatures too.

The first front is expected on Monday, bringing rain and possibly winds over 80km/h with peak gusts over 120km/h, according to the bureau, but the forecast maximum of 13 is still the August average.

''Another front will affect Canberra on Wednesday and probably the most significant front will be during the weekend, most likely Saturday,'' the duty forecaster said.

''During Friday and Saturday, temperatures will rise again ahead of the front. The stronger the front, the higher the temperature we can expect ahead of the front.''

While the severe weather warning is in place, the State Emergency Service advises moving vehicles under cover or away from trees, securing loose items around your house, yard and balcony, and keeping clear of fallen power lines.