I believe Lake of the Woods is 100% ice-free today. So here’s a look at how the spring went, in graphs. You can click on the graphs to see a full-screen, zoomable version.
First, the Brick Graph. Each year gets a brick, and I stack them according to when the ice went out. For simplicity, I divide April and May into five-day periods.
2019 was not an early thaw. Of the last sixteen years, only 2014 was significantly worse, and that was a dismal spring after a brutal winter.
Here’s a slightly more complex graph, that shows not just the date the lake was clear of ice, but the length of time from when it started melting to when it finished. More specifically, each horizontal bar spans the calendar from the Inflection Date, when the mean daily temperature rose above freezing on a lasting basis, to the Thaw Date, when the lake was entirely free of ice.
2019 is at the top, 2018 just below, and so on, down to 2008, the earliest year Sean worked out an inflection date for.
Some fun trivia from this graph: Our inflection date was April 13th this year. 2016 shared the same inflection date, but the lake cleared by May 4th, a full ten days earlier. The ice was probably a lot thinner that spring, because the winter had been mild. 2010 was an extraordinary year: the lake was completely clear by mid-April!
Here’s a graph from Sean that shows how our spring temperature profile compares to other years.
On this graph, all the springs are lined up with Inflection as Day Zero at the left regardless of the calendar date. Each year gets dots in a different colour, and day by day, the mean temperature is added to the rising total. A spring with a string of hot days will produce a steep rise, a cooler spring will show a flatter line. The solid red line is the average for all the years since 2003. 2019 is the thin blue line, and Sean points out that although we did better than average at first, we fell behind about halfway along and never quite caught up.
Anyway, that’s the kind of spring it was, but the lake’s open now. I won’t be doing regular updates any more until next year. I expect I’ll fire up the Ice Patrol again on the first day of spring, or the inflection date, whichever comes first.
Thanks to everyone who came by to visit the website and shared word of it with friends, and a special thanks to my guest photographers and my co-workers at MAG Canada who made it possible for me to offer updates on days when I didn’t fly.
Talk to you next year,