
Wave Watch buoys reveal dramatic water temperature swings in the Apostle Islands National Lakeshore
These may be the longest days of summer, but you'll definitely want to know current wave and water temperature conditions before you jump in for a swim or head out in your kayaak. Due to a relatively cool spring, the largest freshwater lake in the world is about 5 degrees behind normal averages in warming at the surface. The difference between an invigorating swim and potentially life-threatening hypothermia is literally a matter of degrees and timing. And our Wave Watch buoys verify just how quickly conditions can change. Lake Superior's deep-water temperture is 39 degrees year-round but at...


