A cold warning is in effect for most of southern Ontario, excluding Toronto, as a system of very cold air moves through the region.
Environment Canada says wind chill values of between -25 and -30 are expected Sunday night into Monday morning for Mississauga, Brampton, Vaughan, Richmond Hill, Markham, Northern York Region, and Hamilton.
The warning extends from London in the southwestern part of the province as far east as the Quebec border.

Frostbite can develop within minutes on exposed skin, especially with wind chill, and the risks are greater for young children, older adults, people with chronic illnesses, people working outdoors, and those without proper shelter.
While the warnings do not extend to Toronto, temperatures are expected to dip down to -13, feeling like -25 overnight, prompting the City of Toronto to opeing two additional warming centres for anyone seeking a warm indoor place to rest and access meals at 58 Cecil Street and 870 Queen Street East, to go along with the five other centres that are currently open:
Due to the extreme cold temperatures, Toronto officials have dispatched additional Streets to Homes and partner outreach teams to connect with people living outside and encourage them to come indoors.