LIGHTNING strikes caused multiple grassfires in the Ballarat area this afternoon, including one now under control at Mt Warrenheip.
Up to 20 CFA crews and water bombing aircraft were been deployed to help control the blaze, which caused thick smoke to billow across the Ballarat CBD.
Kryal Castle spokesperson Erin Joyce said the venue had been evacuated.
She said the fire came to within around 10 metres of the back wall of the venue.
"We know something was wrong when the lightning hit and there was a lot of smoke very quickly," she said.
"We investigated and called 000 and probably 20 to 30 people were quickly evacuated. The CFA and Parks Victoria were very quick to arrive and looked after us very well."
Ms Joyce said many of the evacuees left the area immediately, while some including tradesmen working on site congregated in a designated evacuation area.
Mahers Road resident Kerry Moran said she saw a lightning strike near Kryal Castle about 3.30pm and within a matter of minutes she could see smoke.
The flames came within about 100 metres of her home, blackening a paddock to her north.
There were reports of fires at Canadian, Dereel, Lake Goldsmith, Mt Emu and Dunnstown, while smoke from a fire in the Carngham area was visible in the Ballarat CBD this afternoon.
A Bureau of Meteorology severe storm warning was issued at 3pm for areas including Ballarat, Bacchus Marsh and Horsham
Heavy rain hit Ballarat around 4.30pm while the town of Snake Valley is also experiencing flash flooding.
While the worst of the storm has now passed, SES crews are expected to attend calls for help around the region tonight.