A pre-winter storm brought a combination of freezing rain, rain and snow to parts of Ontario, Quebec and New Brunswick today.

In Ottawa, the freezing rain led the Ottawa-Carleton District School Board and the Ottawa Catholic School Board to cancel bus service, although schools remained open.

Flight delays and cancellations were reported in Montreal. There were also some delays and cancellations at the Ottawa airport earlier in the day, but flights were largely cleared up by mid-afternoon.

Many of the freezing rain warnings from Environment Canada that covered much of central and eastern Ontario early Monday were gradually lifted as temperatures slowly rose above the freezing mark.

According to Environment Canada, about 10 millimetres of precipitation fell in Montreal overnight. The low-pressure system was expected to clear Monday evening and make its way to northeastern Quebec, where five to 10 millimetres of rain are expected.

Some parts of central Quebec could see up to 20 centimetres of snow throughout the day.

"This area of snow will start to affect the North Shore and the Gaspé Peninsula this afternoon and will continue to do so through the night," Environment Canada said. "Strong easterly winds will affect the lower North Shore overnight and, combined with the snowfall, will produce blowing snow."

The storm warnings come a few days ahead of Quebec's deadline this Saturday for drivers of passenger vehicles and taxis registered in the province to install winter tires. The tires must remain on the vehicles until March 15, or drivers could face fines between $200 and $300.

In New Brunswick, the storm was forecast to drop snow before several hours of freezing rain began.

School was cancelled in some parts of the province, and some university students had exams postponed.

"Rainfall amounts of 20 to 40 millimetres are expected in the south by Tuesday morning with locally higher amounts possible," Environment Canada said.

The weather agency said freezing rain is expected to "persist for several hours over central and northern portions" of New Brunswick.

The storm moved through southern Ontario overnight, causing some treacherous driving conditions. Southbound Highway 400 was closed for several hours just north of Toronto.

The same weather system dumped 25 centimetres of snow — the most in two years — in Minneapolis, Minn., leading officials to declare a snow emergency. Another 15 centimetres of snow was expected Monday.