The SES has received 45 requests for help after a storm brought hail and rain to Canberra on Thursday afternoon.
The number of calls is expected to increase through the evening, with most call outs so far for water in roof cavities, skylight and roof damage and localised flooding.
While some suburbs experienced hail and a large amounts of rain, others experienced only a few drops.
Such patterns were typical of these kind of storms, senior forecaster at the Bureau of Meteorology Jake Phillips said.
"That's often the case when we get a thunderstorm, you can get big variations in rainfall amounts over small areas," Mr Phillips said.
Canberra Airport only recorded four millimetres of rain while Lake Burley Griffin had 10 and Hindmarch 11 millimetres, by 7pm.
It was possible other suburbs not measured by the bureau experienced more rain, Mr Phillips said.
It is unlikely Canberra would see more storms on Friday, but Sunday and Monday were looking likely to produce more storms, Mr Phillips said.
"We're going to see some unsettled days coming up, particularly Sunday and Monday."
Many of the firegrounds around NSW had received rain, Mr Phillips said.
"Most of the firegrounds have seen some rainfall, but again over the fireground it has been quite variable."
Some places near Nowra and Ulladulla experienced more than 30 millimetres of rain.
The ACT Emergency Services Agency warned drivers to take care as slippery roads and reduced visibility in heavy rain with thunderstorms could make driving conditions dangerous.