Lake · Canada, United States
Lake Ontario
Lake Ontario is the smallest of the five Great Lakes by area and the one farthest east. Canada lies on its northern and western shores, and the United States on its southern and eastern shores.
Picture credit: Maksim Sokolov (maxergon.com) (CC BY-SA 4.0) · Andre Carrotflower (CC BY-SA 4.0) · Wikimedia Commons
Where is Lake Ontario?
Countries on its shores: Canada, the United States.
Middle of the lake: 43.70° N, 77.90° W
The story behind it
Lake Ontario gets most of its water from the Niagara River, which tumbles over Niagara Falls on its way from Lake Erie. The water leaves the lake through the Saint Lawrence River. Although it is the smallest Great Lake by area, it is deep, up to 244 metres. Because of this great depth, the whole lake does not freeze over in winter, and ice usually forms only along the shores. In winter the lake brings heavy snowfalls to the land on its southern and south-eastern shores; in some places more than six metres of snow can fall. Toronto, Hamilton and Kingston in Canada and Rochester in the United States lie on its shore. The lake has around 1 500 islands, and the biggest one, Wolfe Island, sits where the water flows out. Its name probably means 'lake of shining waters'.
Find it on the globe
Lake Ontario is there as a small blue dot with its name, right on the water. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.
Questions children ask
How big is Lake Ontario?
Lake Ontario covers about 19 000 km², which makes it the smallest of the five Great Lakes by area. Canada and the United States each own roughly half of it.
Does Lake Ontario freeze in winter?
Because the lake is so deep, it does not freeze over completely in winter. Usually ice forms only along the shores.
What does the name Ontario mean?
The name probably comes from an Iroquoian word meaning 'lake of shining waters' or 'beautiful lake'. The Canadian province of Ontario carries the same name.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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