Ice-In for 2025

Observing the lake yesterday, I thought, "This is a real ice-in day, with the whole lake becoming frozen at once!" I did see some swans in the bay in the distance, but I felt that if nothing opened up with wind or changed, yesterday would be THE DAY.

This morning confirms it, seeing the snow covering the whole lake and not revealing any dark water left open. So as I looked over the frozen scene this morning, I confirmed yesterday's ice-in, December 4, 2025.

Ford Halvorson has won this ice-in pool with his guess of 12/4 in the afternoon - 
Congratulations!

How fast does ice form on a lake? Here's some math for you all to do:

Estimating Ice Growth with Freezing-Degree Days 
You can estimate ice growth using the Freezing-Degree Day (FDD) formula: 

1. Calculate the average daily temperature (High Temp + Low Temp) divided by 2.
2. Calculate FDDs by subtracting the average temperature from 32°F (or 0°C).
3. Estimate new ice thickness by dividing the total accumulated FDDs by 15. 

Example: If the average temperature for a 24-hour period is 20°F:

• FDDs = 32°F - 20°F = 12 FDDs
• Estimated new ice growth = 12 / 15 ≈ 0.8 inches in that day. 

Safety First
These calculations are only guidelines. Ice conditions can vary dramatically even within a few feet. 

• Snow Cover: Even a thin layer of snow acts as a thermal blanket, significantly slowing the freezing process.

As always, be careful on the ice, folks. The Minnesota DNR's standard ice warning emphasizes that NO ICE IS 100% SAFE, but provides thickness guidelines for clear ice: 4 inches for walking/fishing, 5-7 inches for ATVs/snowmobiles, 9-12 inches for cars, and 13-17+ for trucks, advising you to double thickness for white ice, wear life jackets, carry ice picks, and check conditions often as factors like snow and currents make ice unpredictable. The MN DNR has a great webpage about ice safety:
https://www.dnr.state.mn.us/safety/ice/index.html, and do check out the
video on what to do if you fall in: https://www.dnr.state.mn.us/safety/ice/survival.html

Happy Winter to you all!
Anne