The ACT Rural Fire Service will not patrol the fire overnight, because of a lower danger level compared with the weekend when it caused considerable concern.

Firefighters will return to the fire on Tuesday morning to search for hot spots.

The blaze was sparked by lightning last Wednesday night and was contained at one hectare but by the next morning the fire had doubled in size to two hectares.

Extreme conditions across south-eastern Australia kept emergency services occupied through much of the weekend. At one stage, soaring temperatures, dangerous winds and dry conditions threatened to push the fire in the Namadgi National Park past containment lines on to the Monaro Highway.

But lower temperatures on Monday gave firefighters a much-needed break following the most dangerous fire day so far this summer.

The fire remains at 'advice' alert level, meaning there is no immediate danger.