Environment Canada issued the advisory on Thursday afternoon. The agency said periods of rains, heavy at times, with isolated thunderstorms are expected tonight into Friday.
“Rainfall amounts will generally be in the 20 to 40 mm range, with locally up to 50 mm possible in thunderstorms in some locales,” Environment Canada said.
York, Peel, Durham, and Halton regions are also under a special weather statement.
The rain will taper off by noon Friday.
The temperature on Friday will reach a high of 11 C. It will be a mix of sun and cloud on Saturday with a high of 9 C. Showers are in the forecast on Sunday with a high of 10 C.