A blast of winter weather cancelled about 150 flights to and from Toronto's Pearson International Airport Wednesday, with airlines warning of travel disruptions Thursday.

With a mix of rain, snow and ice pellets falling across the city, airlines posted travel alerts to their websites and urged travellers to check their flight's status before heading to the airport.

Rain was forecast to persist through the afternoon that will "quite likely" turn to freezing rain overnight, Environment Canada said in a statement. Light snow is in the forecast for Thursday.

Air Canada had nearly three-dozen travel alerts on its website Wednesday for cities in Ontario, Quebec, parts of the East Coast and a large swath of the U.S. northeast.

The airline is warning that flights to or from these cities, including Toronto, Montreal, New York, Boston, Chicago, Philadelphia, Washington, Fredericton and Saint John, could be delayed or cancelled due to forecasted freezing rain.

As a result, Air Canada is allowing passengers on affected flights to rebook without penalty, space permitting.

By early Wednesday afternoon, the airline had 15 alerts in place for Thursday.

Air Canada and Porter Airlines flights out of Toronto's Billy Bishop Airport also had delays and cancellations listed through Wednesday afternoon and evening.

weather advisory on Porter's website said that the "unfavourable" weather "may result in flight cancellations or delays." The airline will also waive change fees if a flight is cancelled or delayed and a booking must be modified.