Frost is seen on the ground in Ingersoll, Ont., in this photo from November 2012. (Betty Price / MyNews)

OTTAWA - A frost advisory has been issued for Ottawa.

Environment Canada says temperatures are expected to drop to near or below the freezing mark overnight Friday. The low is expected to be -2 C.

Environment Canada is advising residents to take preventative measures to protect their trees and plants.

Saturday is expected to warm up slightly, with a high of 13 C and a low of 6 C overnight.

Sunday will be cloudy with a chance of showers and reach a high of 18 C.