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How Deep is Lake Ontario? Fun facts, Map, and More

How Deep is Lake Ontario? Fun facts, Map, and More

Lake Ontario is one of the Great Lakes and lies 325 ft (99 m) below Lake Erie, at the base of Niagara Falls. Lake Ontario’s average depth is 243ft and has a maximum depth of 802ft. By surface area, it is the 13th-largest lake in the world.

Lake Ontario holds almost four times more water than Lake Erie and ranks fourth among the Great Lakes in maximum depth. However, its average depth is second only to Lake Superior.

Tourism and Leisure

There are many things to do when visiting Lake Ontario. The beaches are a great place to relax and enjoy the scenery. There are also many cultural and natural attractions to visit. If you’re looking for a more active vacation, you can go swimming in Niagara Falls or take a tour of the Toronto Islands. 

Lake Ontario is also home to many different species of fish and wildlife. You can go fishing, canoeing, or kayaking on Lake Ontario. There are also many parks and nature reserves to visit.


The climate around Lake Ontario is generally warm, with extreme high and low average temperatures throughout the record. However, recent average temperatures are usually higher than in the past due to a warming trend in air temperature in the Lake Ontario basin from 1948 to 2014.

Geography and Hydrology

Lake Ontario is amongst North America’s five Great Lakes. The Canadian province of Ontario binds it to the north, the U.S. state of New York to the south, and the Canadian province of Quebec to the east. Lake Ontario is the smallest and shallowest of the Great Lakes, with an average depth of 243 feet (74 meters) and a maximum depth of 804 feet (245 meters).

The lake’s primary inflows are from Lake Erie and the Niagara River, both from the south. The lake’s only outflow is via the Saint Lawrence River towards gastro-Canada and thence to the Atlantic Ocean.

Lake Ontario was formed about 12,000 years ago by melting glaciers during the retreat of ice age glaciers. The resulting freshwater lake was much smaller than its current size. It has since been greatly enlarged by natural processes such as erosion and sediment deposition and human activities such as dam construction and engineering works designed to raise its level.

Today, Lake Ontario is a vital part of local and regional economies; it supports a diverse range of recreational activities, including boating, fishing, swimming, and birdwatching; it provides drinking water for millions of people in Canada and the United States.

The hydrology of Lake Ontario is complex, with numerous inflows and outflows. The primary influx is from Lake Erie, which contributes about two-thirds of the lake’s water. Other significant inflows come from the Niagara River, the Genesee River, and smaller streams.

The central outflow from Lake Ontario is via the Saint Lawrence River, which flows to the Atlantic Ocean. The lake also loses water to evaporation; on average, about 538 billion gallons (2 trillion liters) per year.

Lake Ontario has a surface area of 7,340 square miles (19,059 square kilometers). It is approximately 193 miles (311 kilometers) long and 53 miles (85 kilometers) wide at its widest point. The lake has a maximum length of 276 miles (444 kilometers) and a maximum width of 107 miles (172 kilometers).

Lake Ontario has a depth of 804 feet (245 meters) at its deepest point. The average depth of the lake is 243 feet (74 meters).

Canoeing on lake, Ontario, Canada

Fun Facts

Lake Ontario is one of the Great Lakes of North America. It is fourth in size among the Great Lakes, but its average depth is second only to Lake Superior. The lake is in the province of Ontario, Canada, and its name comes from the Iroquoian word ontarío, meaning “great lake.”

Niagara Falls is one of the most famous attractions in the world, and they are located on the Niagara River, which flows into Lake Ontario. The falls were an obstacle to navigation into the upper lakes until the Trent-Severn Waterway, and the Welland and Erie canals were built.

Settlements and Activities on the Lake

European settlements have been documented on the lake since the early 1600s. The lake was the border between the Huron and their vassals and the Iroquois Confederacy in pre-European times. After the French and Indian War, forts on the U.S. side of the lake became American. European settlement had begun during the American Revolution. After the War of 1812, the lake became the center of a thriving business district.

Lake Ontario Map

“Ontario” comes from the Iroquois word ontarío, meaning “great lake.” Lake Ontario is the largest of the Great Lakes and the 14th largest freshwater lake in the world. The lake is located in southern Ontario, Canada, bordered by New York State to the south and east.

Lake Ontario

There are over 30 000 islands in Lake Ontario, most of which are uninhabited. Some of these islands are home to significant bird populations, such as the gull colony on Toronto Island. The lake also provides drinking water for millions of people in Ontario and New York State.

Where is Lake Ontario’s deepest point?

Lake Ontario Rochester Basin

The deepest point in Lake Ontario is Rochester Basin. It is located in the southeast corner of Lake Ontario and is approximately 802 feet (244 m) deep. The deepest point in Lake Ontario, Rochester Basin, is located just south of the city of Rochester.

Is Lake Ontario safe for swimming?

Lake Ontario is a freshwater lake, which means it’s safe for swimming. The water in Lake Ontario is not salty like ocean water, so there are no sharks or other dangerous creatures that live in it. Swimming in Lake Ontario is a great way to cool off in the summer and take a refreshing swim in the winter.

Does Lake Ontario have RIP current?

RIP currents are solid and often unexpected flows of water that pull you away from the shore. They are usually created by natural causes, such as the effect of waves crashing on a beach (the breaking waves push water away from shore) or tidal currents. They can be deadly if they sweep you out to sea or up against a rocky coast.

Lake Ontario does not have RIP currents. The shape of the lake, with its narrows at the Niagara River and wide mouth at Lake Erie, helps keep water moving slowly in a circle. The gentle flow stops ripping currents from forming. RIP currents are standard on the Atlantic coast and the Gulf of Mexico.