Emergency Services Agency spokesman Darren Cutrupi said the worst of the storm had lasted barely an hour but prompted 30 calls for help, including a call-out to Kaleen where a large tree and several smaller ones fell on to a house. But he said the damage to the Kaleen home was ''not serious''.

''Generally the jobs across the board, we haven't seen any great deal of damage. It's mostly fallen tree branches and some leaking roofs.''

There were no reports of hail, although wind gusts reached 70km/h in Canberra and hit 107km/h at Montague Island, off the South Coast.

The storm also brought much-needed rain to the region. At Canberra Airport, 10.2mm of rain was recorded; Ginini received 12.2mm; and 13.4mm was recorded in Tuggeranong.

A Bureau of Meteorology spokesman said the thunderstorm was caused by a line of storms that began in the NSW Riverina yesterday and moved eastwards.

The spokesman said the storm had been associated with a south-westerly wind change moving across the state.

He said showers would continue this morning but would clear by afternoon.