I checked the 2' water temperature on the WeatherCenter Cam page early this morning. It was still just under 37 degrees.
Right now it's reading 39.7! I'm not sure if it actually rose that fast, or if it just hadn't been updating for awhile.
In any case, if the reading is true, it's at the seemingly magic 40 degrees when ice-out happens quickly. The Water Temp page on this site shows the Lakeport Dam at 38 as of today.
On Sunday when I was there, there was almost no open water on the shoreline of Merrymeeting. Now you can see it is at least 20' out.
http://65.175.138.198/view/view.shtml