The slightly warmer temperatures the region has seen in recent days are about to give way to a cold arctic air mass that will usher in frigid temperatures that could fall as low as -21 C by Friday.
The temperature during the morning commute will hover around -8 C, but it will feel closer to -13. The high on the day is -14 C, with temperatures dropping in the afternoon and a 40 per cent chance of flurries. The overnight low is -23 C, which will feel closer to -29 with wind chill.
Environment Canada has issued extreme cold weather warnings for large swaths of southern Ontario, including Halton-Peel.
You can read the full Toronto forecast here.
The TTC is facing some problems this morning. The 134 Progress is diverting both ways near Markham Road due to a broken water main that has forced police to close a stretch of Progress Avenue.
The 71 Runnymede is also diverting southbound at Windermere Road due a large sinkhole that formed last night near The Queensway and Coe Hill Drive.
The 502 Downtowner and 503 Kingston streetcars have been replaced by buses once again this morning due to the winter cold.
The eastbound and westbound Hwy. 401 are starting to fill up, but no major collisions have been reported. Traffic is also picking up on the eastbound Gardiner Expressway and southbound Hwy. 404.
You can check out CBC's live GTA traffic map here.
Most GO Transit buses and trains are all running on time so far this morning, however the Kitchener train is experiencing 12-minute delays due to a technical issue.
You can find TTC service alerts here and GO Transit service updates here.
Flights at Toronto Pearson and Billy Bishop are also running on schedule this morning.
A man was injured during an industrial accident at Union Station overnight. According to police, the man was hit in the back of the neck by a hammer that fell from a height of about nine metres, or 30 feet.
Rob Ford may not be Toronto's mayor any more, but he's still finding his way to the spotlight. The councillor was ejected from Toronto city council on Wednesday afternoon, after he refused to apologize for comments he made about city staff.
A Toronto man found guilty last October in the kidnapping and sexual assault of a young girl in 2011 will be sentenced today. Ryan Belbin was found guilty of breaking and entering, abduction of a person under 14, sexual assault and sexual interference.
The Raptors are heading into the all-star break on a high note with a 95-93 win over the Washington Wizards at the ACC last night. They will resume league play on Feb. 20.
The Leafs are heading to New York tonight to play the Islanders. The puck will be dropped at 7 p.m. ET.