May 14, 2019: All Clear

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,


20 thoughts on “May 14, 2019: All Clear

  1. Thanks Tim! Have a great summer.

    James E. McLandress, BA, LLB, ICD.D
    General Counsel
    Winnipeg Airports Authority Inc.
    249-2000 Wellington Ave.
    Winnipeg, Manitoba, Canada R3H 1C2

  2. Thank you from Calgary!! Live your blog.

    I miss Shoal Lake so much – this gives me a little bit of that old spring fever I felt for 20 years from the mid 70’s to 1997 when I moved west.


    Al Kinnear

  3. Thank you so much for this every year.  I live in Victoria BC  and book my flight to Wpg depending mostly on your information.  And a little on the weather network. Most appreciated.  Judy

  4. Thanks for all of this Tim. You do an amazing job.
    Enjoy the summer!
    Cottage Owner,
    Channel Island, LOW

  5. Great job as usual !!! I have been getting your posts for several years now and always look forward to the next year. The information is always fantastic . Keep up the great work.

  6. Tim – Thank you for all you do to keep us all informed as to when we can get out and enjoy the lake. Much appreciated. Paul L.

  7. I loved and appreciated your updates very much! Job well done my friend!!!

    Eric Brown

    Sent from my iPhone

    Eric Brown

    Sent from my iPhone >

  8. Another great year of reporting! Job well done! Much appreciated!

    Scott Widman
    2nd Judicial District

  9. Excellent job as always, appreciate the methodical approach to analyzing the spring thaw!



    Jamie Paterson
    Industrial Arts Teacher
    John W. Gunn Middle School

  10. Great work again,on the is a pleasure to read and to all who contribute WELL DONE.
    Have a great fishing season
    Be safe out there.

  11. Thanks for all the info. I look forward to it each year. Keep up the great work. Steve Toni

  12. Many thanks for your almost daily posts about ice conditions on Lake of the Woods. They get better every years with the addition of graphs and comparisons to former springs. So looked forward to them that I am almost sorry the lake is finally clear!!

  13. Hi tim- thanks to you and your contributors, once again. It is great what you do, and really appreciate the time and effort put into this terrific project you have undertaken. Thanks again, and will be with you again next year!!

    Terry Fyke
    Employee Benefits Consultant

  14. Hi Tim,

    Once again you’ve provided me and my family with great information and insights on the Lake of the Woods thaw. We love the pictures and watch closely as our area opens and we’re able to get out to our island. The five seasons – Spring, Summer, Fall, Winter, and Ice Patrol . . .


    On Tue, May 14, 2019 at 8:02 PM Lake of the Woods Ice Patrol wrote:

    > icecaptain posted: “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 wh” >

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