Parts of southern Ontario under frost warnings as weather begins to ...

Birds swim in the waters of Lake Ontario as the Toronto skyline looms in the background in Mississauga, Ont., Thursday, Jan. 24, 2019. THE CANADIAN PRESS/Nathan Denette

Large parts of the Greater Toronto and Hamilton Area have been placed under a frost advisory as colder weather begins to set in.

Environment Canada issued a frost advisory Sunday morning, saying temperatures could drop overnight into Monday morning.

“Cover up plants, especially those in frost-prone areas,” the weather agency said. “Take preventative measures to protect frost-sensitive plants and trees.”

The advisory was issued along a stretch of Lake Ontario from Burlington to the edge of Pickering, extending northwards around Toronto as far as Brampton and just below Vaughan.

Areas around St. Catharines, Niagara Falls and Welland were also under a similar advisory.