More than 100 flights to and from destinations including Quebec and the eastern U.S. were cancelled or pushed back after a similar number of cancellations a day before.
Greater Toronto Airports Authority spokesman Scott Armstrong said the impact of snow at the airport Saturday, as well as a storm that was hitting northeastern states, were responsible for the scrapped or delayed flights.
Armstrong said it was hoped the leftover cancellations from the start-of-weekend Ontario snow would be cleared by Sunday evening, though he warned there could be more changes to flight schedules due to the U.S. storm.
Travellers were advised to check the status of their flights before heading to the airport.
Meanwhile, Eastern Canada was bracing for snowy start to the week, with winter storm warnings issued for all of New Brunswick and Prince Edward Island for overnight Sunday and Monday morning.
Environment Canada said strong winds in those provinces could cause blowing snow and near-zero visibility driving conditions.
About 20 to 40 centimetres of snow was expected to fall in New Brunswick, while P.E.I. was expecting about 15 to 25 centimetres.
A handful of arrivals and departures at New Brunswick's Saint John Airport were cancelled, as well as a few at the Greater Moncton International Airport.
Marine Atlantic cancelled both of its crossings between North Sydney, N.S., and Port Aux Basques, N.L., on Sunday.
The Confederation Bridge — which connects P.E.I. and New Brunswick — was also warning that high winds could interrupt service.
Although Nova Scotia was expected to escape the wrath of wintry weather, wind warnings were issued across the province, gusting to 100 km/h in some areas.
The national forecaster said an intense low-pressure system southwest of the Maritimes was crossing central Nova Scotia on Sunday evening and would move northeast towards the Gulf of St Lawrence on Monday morning.
The storm was then expected to hit Newfoundland and Labrador, bringing 15 to 30 centimetres of snow to some areas by Monday evening.
Environment Canada also warned of strong southeasterly winds gusting to 130 km/h in coastal regions of the island.