Southern Ontario
Southern Ontario has a very different climate from the rest of the country. It is the only area of Canada that has Carolinian forest. Many trees, plants, and wildlife in Southern Ontario are not found anywhere else in Canada. Some rare trees to Canada in this region include the tulip tree, pawpaw fruit tree and the cucumber tree. The Carolinian forests of Southern Ontario have in large part been destroyed by development sprawl. Very few original growth areas remain.
Ontario
The climate of Ontario varies by season and location. It is affected by three air sources: cold, dry, arctic air from the north (dominant factor during the winter months, and for a longer part of the year in far northern Ontario); Pacific polar air crossing in from the western Canadian Prairies/US Northern Plains; and warm, moist air from the Gulf of Mexico and the Atlantic Ocean. The effects of these major air masses on temperature and precipitation depend mainly on latitude, proximity to major bodies of water and to a small extent, terrain relief. In general, most of Ontario's climate is classified as humid continental. Ontario has three main climatic regions.