Forecasters are warning more wild weather could hit eastern New South Wales following a week of damaging storms.
The storm passed quickly over Sydney about 3.30pm - but it was long enough to cause blackouts for some suburbs including Hornsby, Asquith and Turramurra in the northern suburbs, the ABC reported.
Dozens of extra State Emergency Service (SES) volunteers have travelled to Sydney from regional New South Wales to help weary crews with the aftermath of the week of storms including one yesterday which left 10,000 properties without power, mainly in Sydney's north and west.
The SES dealt with almost 750 incidents of flooding and damage after Sunday's storm.
The Bureau of Meteorology said more storm activity was recorded at Sydney Airport this morning, making today a record-breaking seventh straight day of storms in the city.
"The previous record was five consecutive days of thunderstorm activity," meteorologist Rob Taggart said.
Six SES crews, of about five volunteers each, have travelled to Sydney.
Spokeswoman Nat McLean said many Sydney volunteers were exhausted.
"They've been going now for quite a few days and we needed to bring in some extra help for them," she told 702 ABC Sydney.
"They're still doing a lot of clean-up today. We've had about 736 jobs from the beginning of [Sunday's] event, mainly in the Sydney northern region, which encompasses Ku-ring-gai, Hornsby, Waringah, Camden and Hawkesbury.
"It's mainly leaking roofs, smashed tiles, trees through properties - so it's been quite a mess."