That would be 2016 - earliest ice-out ever - March 18. Beat the old record by five days. I remember it well as it was our first winter on the lake. I had heard all these stories about the lake getting locked in each winter and after that season I thought "well..that wasn't so bad".
It is interesting to note that the three earliest ice-outs in 135 years of recording all occurred in the last nine years. Global warming? Coincidence? Too many bubblers
. I don't know but not being a winter fan, I welcome the trend.