Heavy rainfall and slow-moving thunderstorms are expected to move across southwestern Ontario on Friday.
Environment Canada issued a rainfall warning on Friday morning for several areas including Sarnia-Lambton, Chatham-Kent, and Windsor-Essex.
However, a special weather statement has been issued for Perth County, Huron County, Grey County and North Wellington.
London-Middlesex was briefly under a rainfall warning but the advisory was downgraded to a special weather statement at 10:43 a.m.
The rainfall warning ended for Sarnia-Lambton just before 2:30 p.m.
The national weather agency said rainfall amounts of 30 to 60 millimetres are possible.
The possible heavy rainfall is expected to continue into the evening hours.