If you're heading up to the cottage this weekend or planning a camping trip, make sure to pack some warm clothing.
And if you were planning on doing some gardening, you may want to hold off until next week.
Environment Canada has issued a frost advisory for parts of southern Ontario. Areas affected include Milton, Caledon, Newmarket, Vaughan, Richmond Hill, Markham, southern Durham region, and areas up north.
The weather agency says frost will end this morning as the temperature rises but will likely redevelop tonight as temperatures drop to near freezing marks.