Facts about Lake Superior

Lake Superior is one of North America's most iconic natural wonders, captivating visitors with its sheer size, beauty, and mystery. Known as the largest freshwater lake in the world by surface area, Lake Superior holds countless fascinating stories beneath its waves. From its geological history to its chilling waters and shipwrecks, here’s an in-depth look at some amazing facts about Lake Superior.

Fact	Detail
Location	United States (Michigan, Minnesota, Wisconsin) and Canada (Ontario)
Surface Area	31,700 square miles (82,100 square kilometers)
Length	350 miles (563 kilometers)
Width	160 miles (257 kilometers)
Average Depth	483 feet (147 meters)
Maximum Depth	1,333 feet (406 meters)
Volume	2,900 cubic miles (12,100 cubic kilometers)
Shoreline Length	2,726 miles (4,387 kilometers) including islands
Elevation	600 feet (183 meters) above sea level
Outflow	St. Marys River to Lake Huron
Formation	Formed by glacial activity over 10,000 years ago
Major Cities	Duluth (Minnesota), Thunder Bay (Ontario), Marquette (Michigan), Superior (Wisconsin)

1. It’s the Largest Freshwater Lake by Surface Area

Lake Superior covers a staggering 31,700 square miles (82,100 square kilometers). That’s roughly the size of Austria or about half the size of the entire United Kingdom. Its sheer scale makes it the largest freshwater lake in the world by surface area and the third-largest by volume.

2. It Holds 10% of the World’s Fresh Surface Water

Lake Superior contains approximately 2,900 cubic miles (12,100 cubic kilometers) of water—about 10% of the world’s available fresh surface water. If the water in Lake Superior were spread out across North and South America, it would cover the continents with a foot of water!

3. Lake Superior is Incredibly Deep

The average depth of Lake Superior is around 483 feet (147 meters), while its deepest point plunges to 1,333 feet (406 meters). Interestingly, the bottom of the lake at its deepest point is about 733 feet below sea level, even though the lake's surface is about 602 feet above sea level.

4. It Was Carved by Glaciers

Lake Superior was formed during the last Ice Age, roughly 10,000 years ago, as retreating glaciers carved out the basin and filled it with meltwater. Its rocky shoreline and steep cliffs are remnants of the ancient Canadian Shield, some of the oldest exposed rocks on Earth, dating back over 2.5 billion years.

5. The Water is Very Cold, Even in Summer

Even in the warmest months, Lake Superior’s surface temperature rarely rises above 55 to 65°F (13 to 18°C) in most places. Deeper areas often stay in the 30s and 40s°F (1 to 9°C) year-round, making it dangerously cold for extended swimming.

6. Lake Superior Creates Its Own Weather

The lake’s vast size influences regional weather patterns, a phenomenon known as lake-effect weather. In winter, it contributes to heavy snowfall along its shores, particularly in Michigan’s Upper Peninsula. In summer, it can create sudden and severe storms, making navigation perilous.

7. It’s Home to Over 80 Species of Fish

Lake Superior boasts a rich ecosystem, home to native fish like lake trout, whitefish, brook trout, and walleye. It also has populations of salmon and steelhead that were introduced to boost sport fishing. The lake’s cold, clear waters make it an excellent environment for fish.

8. It Has Thousands of Shipwrecks

Due to its size and sometimes violent storms, Lake Superior has claimed many ships over the centuries. It’s estimated that more than 350 shipwrecks lie beneath its waters. The most famous is the SS Edmund Fitzgerald, which tragically sank in 1975 during a fierce November storm, claiming all 29 lives on board.

9. Isle Royale is the Largest Island

Lake Superior is home to Isle Royale, the largest island within the lake. Covering about 207 square miles (535 square kilometers), Isle Royale is itself surrounded by more than 400 smaller islands. The island and its surroundings are protected as Isle Royale National Park, a remote wilderness popular with hikers, canoeists, and wildlife enthusiasts.

10. The Water is Exceptionally Clear

Lake Superior's water is among the clearest of the Great Lakes. In some places, visibility exceeds 60 feet (18 meters). This clarity is due to low nutrient levels and the fact that the lake has relatively few inflowing rivers carrying sediments.

11. It Has Its Own "Tides"—Sort of

While traditional ocean tides are absent, Lake Superior experiences seiches, which are oscillating water movements caused by changes in atmospheric pressure and strong winds. These seiches can cause the lake's water levels to fluctuate by several feet within just a few hours.

12. The Name Has Indigenous Roots

The Ojibwe people, one of the Indigenous groups living around the lake, call it "Gichigami" or "Gitche Gumee," meaning "Great Sea." The name "Lake Superior" was later given by French explorers, who called it "Lac Supérieur," meaning "Upper Lake."

13. It Has a Relatively Low Water Temperature Year-Round

Even at its warmest, the lake's average annual water temperature is only around 40°F (4°C). This coldness is one reason why Lake Superior's shipwrecks are often well-preserved—bacteria that would normally cause wood and iron to decay don't thrive in such cold conditions.

Conclusion

Lake Superior is truly a natural wonder—vast, deep, cold, and full of mystery. Its massive size, fascinating history, and vital ecological role make it not just a lake but a world unto itself. Whether you visit its rugged shores, sail its icy waters, or explore its underwater wrecks, you can't help but be awed by the majesty of "The Greatest of the Great Lakes."