Winter Water Temp

[Bigfishhunter]

I monitor water temp very closely in my fishing logs during the summer time. I know that when I am seeing fast fluctuations my fishing will suffer, but this is during the summer.

How often does the water temp fluctuate in the winter, I mean I guess the surface is probably around freezing, and I am also assuming that the layer of ice and snow help to stabilize things from moving up and down as fast as in the summer. Any of you guys ever thought about or monitored this?

Just got thinking so I thought I would ask.

[no1son]

Under the ice in most bodies of water the temp variation is going to be between about 40, which is where water is most dense, at the warmest possible on the bottom to 32 at the ice/water barrier. In most places the bottom has to be 40 before the surface can freeze. That does not translate as well on super sized bodies like the Great Lakes or rivers and streams with any kind of decent current but for for most lakes and ponds it holds quite well. So you don't normally get the kind of temperature variation under the ice that is possible in open water.

A lot of lakes have two turnovers in the autumn, the first breaks the thermocline and the second flips the warmest water to the bottom so that the top can freeze.

There simply can't be as much temperature variation because liquid water cannot get colder than 32 degrees no matter how cold the air is, and as long as there is an ice cover, it cannot get warmer than 40 either which will be on the bottom no matter how warm the air.

Other things like daylength, light intensity, pressure fronts do affect fish under the ice, even if there really isn't all that much temperature variation under the ice compared to what one finds in the summer. Yeah I've thought about it. Water temperature is a far more important variable during open water periods IMO when the water temperature can actually fluctuate a whole lot more.

[Bigfishhunter]

Thanks for the reply. That is exactly what I wondering, i thought it might be something along those lines but couldn't quite grasp how it all worked. I have been enlightened. Thanks again.;)

[Mr.Bluegill Guide Service]

One thing to look for is any variance in water temps under the ice....a degree to a fish is like 10 to us. After years of taking notes on the water i have found that with clear ice and weeds on the bottom the water will warm more that 39.8 degrees into the low 40's. Always have active fish when that happens. second, i look for channels that have natural springs from houses draining into the channel through seawalls or somethin like that. here you will have a degree or 2 warmer water plus added oxygen because of the open water spot that is trickling int the water. 3 if you have emmergent weeds such as cattails or cane beds, the sun will radiate the heat through the stalks warming the water beneath the ice attracting bugs which attract fish. as the winter turns to spring, you get runoff near shorelines and where creek mouths dump into lakes, here again, new oxygen, warmer temps, attract baitfish, bugs and fish.also i have found that dirty water is usually warmer as clear water is usually cooler.

Again just my observations over the past 10 years or so of spending 100 or more days on ice each year.

Good Luck
Mr.B

[Backwater Eddy]

This is a great question and great feedback.

My personal theory is dissolved O2 is more of a key factor as to location under the ice.

Secondly water clarity/turbidity,......... and thirdly all the stuff I don't know...and that is a lot.