A storm brews over Lake Burley Griffin on Sunday afternoon.

A storm brews over Lake Burley Griffin on Sunday afternoon. Photo: Melissa Adams

A brief storm swept through Canberra on this afternoon, with 1.2 millimetres of rainfall recorded at the airport.

It brought with it a cool change, which saw the temperature drop ten degrees in an hour from 5.30pm, with maximum temperatures forecast to remain in the mid-20s early this week.

Further north, severe storms hit various parts of NSW.

A storm brews over Canberra on Sunday afternoon.

A storm brews over Canberra on Sunday afternoon. Photo: Melissa Adams

The Bureau of Meteorology issued a severe thunderstorm warning for Sunday afternoon for people in parts of Sydney's west, as well as parts of the Hunter, Illawarra, Central Tablelands, Southern Tablelands and South West Slopes regions.

Severe thunderstorms were detected on the radar near Oakdale and Picton and storms impacted areas in the west of the state, including Penrith, Bathurst, Katoomba, Goulburn and Young, before moving northeast.

The warnings issued said large hailstones and heavy rainfall was likely, which could lead to flash flooding.

With AAP