Residents in Huron and Perth counties who have already begun their spring planting will want to cover their plants Wednesday night.
Environment Canada has issued a yellow-level frost advisory for the region, advising that patchy frost is expected to develop overnight into Thursday morning as the temperature drops to near or below freezing.
The frost could cause damage to plants, trees, and crops, the national weather agency added.
Anyone who already has plants out is advised to cover them up with burlap or an old sheet to protect against the frost.
The temperature is forecast to fall to 0 C overnight, well below the average low for this time of year of 6 C.
Temperatures are expected to remain below seasonal through early next week.
