Ice Data

This page has information gathered by  Sharon Natzel with help from several observers around the lake. They check the lake to determine the dates that the lake freezes over and the dates when it thaws in the spring. Once our official ice in or out dates are determined, the data is provided to several agencies, including the MN DNR Climatology Office and the Hubbard County SWCD that track ice.

Explanation of how the data is gathered:  
Long Lake has some very deep spots that make exact dates for the lake freezing over difficult to calculate.  The dates for ice-out in the spring are much easier.  The original Ice-In and Ice-Out data was provided by the late Bella and John Sanders, whose home was near the mid-section of Long Lake.  They collaborated with the late Bill Anderson who lived close to the deepest part of the lake toward the North end. 

Vern Campbell, a friend of Lou Schultz, works on the statistics for Long Lake based on these observations.  Their control graphs allow us to predict our future, average (mean) ice-in date.  The control limits are calculated from the data and are plus and minus three standard deviations from the mean.  The green lines depict the mean or average ice-in and ice-out. The red lines show the control limits or extremes of what can be expected.  They tell us in a stable system (no outside influences) we would only have three years out of one thousand where the ice-in could fall after January 3 or before November 20.

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ICE OUT Data

Click here to see chart of dates used to make these Ice-Out graphs.

2024 Ice Out Date was April 8

According to Vern Campbell: The following are the charts for Long Lake Ice Out.  The average date is April 20, so 2024 was about 12 days earlier than the average.  The charts indicate that although the Ice Out this year was slightly earlier than average, it is still within the bounds of normal random variation.  Just as a reminder, the UCL = May 22 and the LCL = March 19 are calculated values and are +/- 3 standard deviations from the mean date of April 20.  Therefore, basically if dates are normally distributed and fall between May 22 and March 19, then we can basically conclude that any deviation we see from the average is simply normal random variation.  Thus far, the Ice Out dates indicate random variation about the average ice Out date of April 20.

Link:  DNR Median Ice Out Data for the state of MN

(to find Long Lake (# 29016100) DNR data use this link )
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Ice-In was determined be December 18, 2024 

Click here to view chart of dates for Ice In graph

  

From Vern Campbell, our volunteer statistician.

The following are the charts for Long Lake Ice In 2024.  Looking at the chart, over the past 11 or so years, there appears to be a “drift” upwards (or later) in the Ice In chart.  Although strictly speaking, this “drift” is still within the realm of random probability, it is interesting to note.