Why is it just 50 degrees at Duluth Sky Harbor while everyone else is baking in record heat today?

Minneapolis is already at 85 and under a heat warning, it is even in the 70's everywhere else except right along the Superior Coast today. Do Grand Marias, Sky Harbor ever get warm? I know Superior is a frigid lake, but also know it does warm up, so much so that the normal highs are in the mid 70's in July and August even right on the water at Sky Harbor airport. The normal high for today at Sky Harbor airport is in the mid 60's. Common sense tells us that if every other place in Minnesota - including the Duluth airport that is inland will be well above normal, that places on the coast will be above normal as well.