About 15 millimetres of rain fell overnight and up to 30 millimetres more is scheduled to fall today.
Toronto is under a rainfall warning and Environment Canada has issued a special weather statement about the wet weather.
The deluge is causing problems for Friday's morning commute. There is heavy flooding reported on some sections of the Don Valley Parkway.
CBC overnight reporter Tony Smyth captured images of streets flooded on Royal York Drive near Dundas Street West.
Pearson International airport is reporting normal operations.
School bus cancellations
Both the Toronto District School Board and Toronto Catholic School Board will have regular classes today with buses running.
Outside the city there are some school bus cancellations, including:- Dufferin-Peel Catholic District School Board Buses and the Peel District School Board Buses in the Town of Caledon and the County of Dufferin are cancelled today.
- Durham Region public and Catholic schools boards: Buses cancelled north of Highway 7 (Winchester Road).
- Halton District School Board Bus service is cancelled north of Steeles Avenue.
For information about school boards not listed here, please check with your local school board.