I think mostly a product of cold first half of the year- especially the Spring. Regardless, I was struck by-- on the avg - (only 27-28 years is not much in the grand scheme) how quickly the lake on avg warms in July - peaks in Sept (which I did know) but then falls like a rock in Oct. I just thought the process would be more rounded rather than so extreme in the ups and downs as we are talking Lake Superior- not Lake One. Anyways- just thought I would share---