Environment Canada has issued a special weather statement for London and its surrounding region.
According to the national weather agency, London, Parkhill, Strathroy, Komoka and Middlesex County are all expected to be affected by the remnants of tropical depression Gordon.
Environment Canada says the rain will begin this evening and continue into Monday.
By the time the rain tapers to scattered showers Monday night, London and its surrounding regions could receive between 20 mm and 40 mm of rainfall.