Air Canada cancelled all short and medium-haul flights to and from Vancouver on Wednesday because of the snowy weather.
The airline said it also expects to fly a reduced schedule on Christmas Day.
However, it is trying to keep to the schedule for longer flights Wednesday, including ones to and from Toronto, Montreal, Ottawa, London, Hong Kong, Shanghai, Tokyo, Seoul, Australia and Hawaii.
Flights between Alberta and Vancouver were among those cancelled, Air Canada said.
WestJet Airlines, too, is delaying and cancelling some flights.
Environment Canada said Vancouver is getting five to 10 centimetres of snow.
The Vancouver International Airport was close to working through the backlog from Monday's storm when the next blast hit, said Rebecca Catley, director of communications. But by mid-afternoon the runways were clear and operational.
Pearson International Airport in Toronto was also reporting delays, although nowhere near the level of Vancouver's problems.
Most Pearson flights were arriving or leaving within an hour of the scheduled time, the airport's website shows.
"As people try to get home for the holidays, it is going to be one of those very tough-going days," CBC reporter Colleen Jones said.
B.C.'s white December
Several storms have battered much of Canada over the last week, setting the country up to see its first coast-to-coast white Christmas since 1971.
Toronto received up to 20 centimetres of wet snow Wednesday morning, then freezing rain later in the day.
British Columbia has been pounded by one of the snowiest Decembers on record. A storm earlier in the week dumped up to 70 centimetres on B.C.'s southern coast, which usually gets just 55 centimetres in the entire winter.
Officials are advising air travellers to check departure times online and to arrive early.
Airport officials in both Vancouver and Toronto said air travel on Dec. 24 is statistically the second-quietest day of the year, after Christmas Day.
Airports in Victoria, Ottawa, Montreal and Halifax also reported some delays and cancellations Wednesday.
Many Canadians' departure plans were wrecked when more than 300 flights were cancelled at Pearson airport in Toronto after a snowstorm swept through the region last Friday. It caused flight cancellations and significant delays across the country.
The airlines said they added more planes to deal with the backlog, but the delays could take days to clear up.
They're also trying to encourage people not to travel at all, to ease congestion. WestJet has offered passengers a credit worth twice the price of their ticket if they cancel.
Air Canada is allowing travellers to reschedule their flights without paying an extra charge.
In Fredericton, which was pounded by a blizzard Monday, activities at the airport had returned to normal. But bus lines in the province were still struggling to operate on schedule.
Local resident Jennifer Chiasson has been trying since Monday to use Acadian, a bus line, to get to Moncton, N.B., for the holidays.
"Hopefully, there will be enough room because there was already a bus going to Moncton and it was too full, so I have to wait for another one," Chiasson said. "So hopefully, I'll get home for Christmas."
The bus line said it was bringing in extra coaches to deal with the backlog but it was also scheduled to switch to reduced routes for the holidays.
Meanwhile, New Brunswick was preparing to be hit with another blast of winter weather, with the forecast projecting freezing rain for parts of the province. In Nova Scotia and parts of Newfoundland, rainfall warnings have been issued.
In the Prairies, an arctic-weather outflow was freezing the provinces for the second week in a row.