Freezing rain has coated much of the GTA in a layer of ice as a warning remains in effect for much of southern Ontario calling for poor weather conditions to last for "several hours."

"An extended period of freezing rain" is expected to change to rain in the evening, according to an alert issued by Environment Canada.

"Surfaces such as highways, roads, walkways and parking lots may become icy and slippery," the federal agency warned.

They were certainly correct.

Streetcar lines, trees and roadways became coated in a layer of ice, causing traffic delays across the region.

The weather warning led to several GTA school bus cancellations, although nearly all schools were open Tuesday.

Mark Schuster, meteorologist with Environment Canada, said earlier that the freezing rain had been expected to arrive in the GTA sometime after 9 a.m., after the morning rush hour. But around 8:30 a.m., the federal agency updated its alert to say the freezing rain would "begin near noon."

Shortly after 11 a.m., Environment Canada said freezing drizzle was falling in the city.

Pedestrians, be careful out there. There's ice where you don't expect it. <a href="https://t.co/Rgiy0Cs4Sp">pic.twitter.com/Rgiy0Cs4Sp</a> —@wisem

Areas closer to Lake Ontario will likely see the change to rain earlier as temperatures rise above the freezing mark, Schuster said. However, regions farther north should see freezing rain persist into the afternoon or evening.

Schuster called the storm "fast-moving," but said it will not be anything like the ice storm of four years ago.

"This doesn't look to bear any resemblance to the ice storm of 2013," Schuster told CBC Toronto. "While conditions will be quite poor, [we're] not expecting trees breaking or power lines coming down."

Travellers advised to check flights

Ahead of the nasty weather, Toronto Hydro tweeted a link to its information page on how to prepare for extended power outages, including preparing a 72-hour emergency kit.

Winter weather this morning may cause delays & cancellations. Please check flight info with your airline or on <a href="https://t.co/siQEK1eP2c">https://t.co/siQEK1eP2c</a> —@TorontoPearson

Toronto's Pearson International Airport warned that winter weather may cause travel delays and cancellations today. The airport advised travellers to check their flights before leaving home.

Travel Alert– Feb 7: YYZ, YTZ, YUL, YOW, YVR, YYC, YYJ, BOS, DTW & MKE. Details & rebook online. Change fees waived: <a href="https://t.co/JDgEGu99rl">https://t.co/JDgEGu99rl</a> —@AirCanada

Air Canada issued a travel alert, warning passengers travelling through Pearson that they could change their flights on Tuesday without penalty due to the inclement weather.

TTC prepared

The Toronto Transit Commission began preparations ahead of the poor weather on Monday night, by ensuring streetcar lines and outdoor portions of subway tracks remained clear of ice.

For streetcars, the transit agency keeps overhead wires clear of ice by attaching sliders, which are like serrated blades, to the trolley pole. About 20 cars were outfitted with sliders last night, Brad Ross, the TTC's director of communications, told CBC Toronto.

On the subway tracks, some trains on regular service will spray a de-icing agent on the third rail to keep the power source clear.

"We are prepared," Ross said.

"The one piece of advice that we would offer to anybody riding home today and taking public transit ... is to leave yourself lots of time," he said.

By midday, the temperature in Toronto had dipped to -1 C but felt more like -7 C with the wind chill. Winds were coming out of the east at 20 km/h, gusting to between 40 and 60 km/h.

Rain is expected to end late this evening, with wind gusts of between 40 km/h and 70 km/h expected. The temperature is expected to rise to 8 C tonight before falling.