Wondering what the temperature of Lake Michigan is? It’s a reasonable question to ask, as the temperature of the lake has a direct effect on aquatic life and the recreational activities that take place in, on, and around the lake. Fortunately, finding the answer is relatively straightforward. The surface temperatures of Lake Michigan range from a balmy 35 degrees Fahrenheit (1.7 degrees Celsius) during the summer months to a chilly 36 degrees Fahrenheit (2.2 degrees Celsius) in the winter.
How does Lake Michigan remain relatively constant? Firstly, Lake Michigan is part of a larger Great Lakes system, which is composed of five connected lakes and is the largest body of freshwater in the United States. Furthermore, Lake Michigan is open to the flow of the Atlantic Ocean, but at a rate that is slow enough to not affect the temperature of the lake quickly. Therefore, seasonal and annual differences in the temperatures of Lake Michigan are minimal.
More specifically though, the temperatures of Lake Michigan are composed of several factors. Firstly, temperature surface water from the Great Lakes is a combination of temperature from the atmosphere, as well as geothermal energy from the Earth. Furthermore, lake currents and air currents affect the temperature of the lake, and fluctuations in the lake bed temperatures can cause fluctuations in the lake’s temperature. Finally, lake mixing—the process by which lake waters, streams, and rivers mix—can cause further variability.
Higher than average surface temperatures increase the risk of algal blooms, which can result in the water being unsafe to swim in, fish, or boat in. If water temperatures rise too much, it can cause aquatic life to relocate or die off, thus making the lake less productive, and potentially causing severe ecological damage. Thankfully, Lake Michigan is well monitored and regulated, with regular water quality testing and temperature surveillance.
Reflecting on the past, historical data of the Great Lakes system reveals that Lake Michigan was typically warmer in the summer months during the 1980s and 1990s. The last decade, however, has seen temperatures decline. This could be due to climate change, and the resulting cooler water or air temperatures, or it could be attributed to increased efforts to stop the introduction of non-native species into the lake.
Variations In Temperature
In certain circumstances, there can also be variations in temperature throughout Lake Michigan, as well as among the other Great Lakes. For example, the temperature of the lake can be affected by the influx of warmer or cooler water from the surrounding rivers and streams, and the temperatures of tributaries like the Chicago River, St. Joseph River, and Grand River can affect the temperatures of the lake in their areas.
Moreover, other factors such as turbulence and wind direction can also produce greater variations in temperature. For example, on days with strong winds, cooler air masses can cause colder surface water to move downward, which can then disperse into deeper layers of the lake. Furthermore, warm air temperatures can also result in warm surface water temperatures, running in the same direction.
Measuring the Temperature of Lake Michigan
The temperature of can be measured from the lake surface. Ambient air temperatures are typically measured on shore, or at an elevated point by aircraft. In some cases, measurements can also be obtained from satellites, such as the NOAA GOES satellites, which also provides information on wind speed and direction.
In terms of measuring the water temperatures of Lake Michigan, there are two main methods—direct and indirect. Direct methods involve the use of sensors inserted into the lake’s surface, while indirect methods rely on remote sensing technology, such as depth sounding instruments.
In some cases, direct temperature readings from the lake are useful in predicting future temperatures. These readings are often used to assess future water levels, and can help in formulation of water management decisions.
Ice cover of Lake Michigan
Lake Michigan is usually covered in ice during the winter months, with the formation of ice occurring around late November. However, this is not always the case, and the area and thickness of the ice can vary due to natural variations in weather conditions and temperature fluctuations.
In recent years, the lake has seen more frequent fluctuations in the timing and location of ice formation, leading to a range of impacts on the ecology of the lake. The shorter and more variable periods of ice cover have resulted in changes in the lake’s temperature regimes and less predictable levels of snow accumulation on the ice. Such changes can have a long-lasting effect on the lake’s aquatic life.
It is also important to note that the ice cover of Lake Michigan can be affected by anthropogenic activities, such as increased shipping and recreational activities on the lake. As such, lake ice cover can be monitored for compliance with federal and state regulations to ensure the lake remains safe and clean.
Consequences Of Temperature Rising
If temperatures in Lake Michigan do continue to rise, it is important to consider the possible consequences. Warmer lake waters can lead to increased algae growth, which in turn can lead to decreased oxygen levels and deplete the lake’s food-web. Additionally, warmer temperatures can lead to the migration of invasive species, and the destruction of uniquely endemic species.
Furthermore, warmer temperatures in the great lakes can result in reduced fish populations, higher levels of toxic pollutants, and an overall decrease in the biodiversity of the lake. In regards to human activities, increased temperatures could also lead to unhealthy swimming water, decrease catch rates among recreational fishers, and affect the timing of shipping through the Great Lakes.
Effects on Industries that Rely on Lake Michigan
In addition to the potential consequences mentioned previously, increasing temperatures in Lake Michigan could also have significant implications for industries that rely heavily on the lake, such as the recreational tourism, commercial fisheries, and shipping industries. Warmer temperatures can lead to changes in the hydrology, chemistry, and concentration of nutrients in the lake.
As such, if water temperatures continue to rise, businesses reliant on Lake Michigan may need to make adjustments and adopt new techniques in order to accommodate the change. Without such adaptations, these industries could become unsustainable and irreparably damage the economy of the communities that depend on them.
Climate Change
The warming temperatures of the Great Lakes, including Lake Michigan, is becoming a greater and greater concern, and is linked to global climate change. As mentioned previously, temperatures in the lake have declined over the last decade, however, this trend could still reverse if climate change is not addressed.
The effects of global climate change can be seen in the temperature and ice cover of the Great Lakes. With rising temperatures, outbreaks of dangerous algal species are becoming more common, and can be toxic to both people and aquatic life. Additionally, warmer waters have the potential to cause unbalanced food webs and the proliferation of invasive species.
Going forward, there is also the potential for further changes to the lake’s temperature, as well as increased water levels, decreased lake mixing, and greater levels of ocean influence. As such, it is important for individuals, policy makers, and stakeholders to increase awareness about the changing conditions of the lake, for both humans and animals.
Management and Conservation
It is clear that the temperature of Lake Michigan is an important factor to consider in the protection of the environment. As such, there are a number of different management and conservation strategies that can be employed in order to ensure the temperature of the lake remains as close to predetermined temperature ranges as possible.
One example is the development of temperature-based water quality management plans, which can help minimize the impacts of temperature on aquatic species and human activities. Additionally, the use of connected data collection systems are also valuable tools in monitoring temperature fluctuations.
Furthermore, the use of artificial means, such as water towers and air curtains, can help to reduce the impact of fluctuations in temperature. Such methods can also be used in conjunction with best management practices such as fertilization and proper shoreline management.
Finally, the use of artificial cooling systems and thermal exchanges, like the Chicago Sanitary and Ship Canal, can also help to decrease lake temperatures and improve the general health of the lake.
