[Pine Island Guy]

I found this interesting article... for those that want to do play with the calculations

1. Calculate the average temperature of the day by adding low temperature and high temperature and dividing by 2. Use degrees Fahrenheit. Now subtract that average from 32 degrees, the temperature at which water freezes. You have now just calculated what they call “freezing degree days.”

Example: If the low temperature today was 24 degrees and the high was 30 degrees, the average temperature of the day was 27 degrees. Subtract that from 32, and you get 5 freezing degree days for this day.

2. Based on studies, once a thin layer of ice film forms on a lake, it will add 1 inch of ice for every 15 freezing degree days in a 24 hour period.

Example: If we had a day with 5 freezing degree days, you would use the formula 5/15 = .33. On this day you would add .33 inches of ice, or 1/3 of an inch. But remember, this is after the first layer of ice forms.

This shows how long it can take a lake to freeze, even after a cold day.

With the temps this week, we have a lot of "freezing degree days" coming up!! -PIG