A big chunk of Ontario remains under a series of Environment Canada freezing rain warnings.

The warnings cover a region that extends from just north of the Greater Toronto Area up to North Bay, Sudbury and Sault Ste Marie, and east to the Ottawa Valley.

Travellers are warned to prepare for treacherous road conditions Monday afternoon, as well as possible flight delays or cancellations.

Provincial police are advising motorists against driving unnecessarily, while air travellers should check the status of their flights before heading to airports.

Hydro One says ice accumulation on lines or other electrical equipment along with nearby tree limbs may cause damage, and is warning "to be prepared for the potential of an extended outage."

'We urge everyone to be prepared'

The utility began warning customers Sunday it was gearing up to respond to a significant ice storm, heavy snow and high winds threatening most of the province.

"We have been tracking the incoming storm and are getting crews and equipment ready in the areas anticipated to be hardest hit," acting chief operating officer Darlene Bradley said in a written statement.

"While our crews and customer service agents get ready to respond as quickly and safely as possible, we urge everyone to be prepared with an emergency kit and the tools to access the most up-to-date outage information."