Residents hoping for a break from the stormy weather are out of luck.
Environment Canada has issued a special weather statement for the London region warning of thunderstorms with heavy rain possible Friday afternoon into Saturday morning.
London, Parkhill and Eastern Middlesex County are all covered under the statement.
The weather agency says thunderstorms with heavy rain could dump 30 to 60 millimetres as they move through the region. It says higher amounts of rain are also possible due to multiple thunderstorms.
Environment Canada says there is still a lot of uncertainty regarding storm track and rainfall amounts.
A rainfall warning, meanwhile, is in place for Strathroy, Komoka and Western Middlesex County.
Environment Canada is warning of up to 75 millimetres of rain in parts of the region by Friday.
Heavy downpours can cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible.
The special weather statement and rainfall warning come on the heels of a severe thunderstorm that ripped through the region Thursday.
No injuries were reported, but cleanup efforts continue on Friday after a thunderstorm brought down tree limbs and power lines and knocked out hydro to hundreds of customers in London.
There is an unconfirmed report that a tornado may have touched down in the Sparta area.
Inside the city, power lines were down across Tecumseh Avenue in Old South and crews had to remove a tree that brought down hydro wires at the corner of Becher and Perry streets.