With heatwaves and triple-digit air temperatures afflicting much of the United States, there is at least one place that is colder than normal: Lake Superior.
The deepest of the Great Lakes is famously known for its cold depths. But the water on the lake surface usually warms in the summer, sometimes becoming much warmer than normal.
However, in this year of exceptional summer warmth on land—including 90 degree air temperatures across the Upper Midwest—Lake Superior’s water temperatures are running more than 7°F (4°C) below average for this time of year. Such low water temperatures have only occurred twice since 1995.
The map above shows water surface temperature anomalies for July 18, 2022; that is, how much the surface layer of each lake was above or below the long-term average temperature (2003–2014) for this time of year. The data come from the Multiscale Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, based at NASA’s Jet Propulsion Laboratory. MUR SST blends measurements of sea surface temperatures from multiple NASA, NOAA, and international satellites, as well as ship and buoy observations.
Read more at: NASA Earth Observatory
Photo Credit: NASA Earth Observatory by Joshua Stevens