just wonderin' about water temps. . .

[eyewinder]

I don't recall seeing much discussion recently on determining water temperature at depths, and how surface temperature affects walleye activity.

So here goes: Many times (during the spring, especially) surface temperature will vary up to 10 degrees from one day to the next (more often, not quite that much). So how reliable is surface temp as a predictor for walleye activity? And what's the best (and most affordable) way to determine water temperature at the depth where I'm marking fish?

I'm guessing that the best answer is to put my favorite bait at the depth where the fish are showing up, and see what grabs it. . .

[cisco]

Right now, Minnesota lakes are floating ice. Water temps in large bodies of water will be warmest at the deepest holes. Water is most dense at 39.2 degrees Fahrenheidt, thus, "warmer" water will not be the bottom layer. From bottom to top you'll get temps down almost to freezing. Once the surface temps warm to 39.2 degrees, the water will sink through the cooler, less dense water and spring "turnover" occurs. Winds and currents will keep things turbulent until later in the spring when the lakes actually stratify.

Til then, and later, it's largely a hunting expedition.

[Stezostedion vitreum man]

Cisco,

Most of what you say about the fall and spring overturn is correct. However, you stated " thus " warmer " water will not be the bottom layer ", this is not quite correct.

Colder water is usually more dense than warmer water, until it reaches 39 degrees F. or 4 degrees C., however, when it gets colder than that ( i.e. 38*F, 37*F, 36*F, etc.), it becomes less dense and this colder, less dense water then rises to the top, a very unqiue chararacteristic of water, which prevents the lake from freezing from the bottom up, thus preserving most of all the living organisms.

Therefore, after the fall turn over, the lake is of equal temperature from top to bottom. As the weather gets colder and cools the surface waters, this cooler more dense water begins to sink. This continues until it cools down to the magic number of 39 degrees F., then begins to rise towards the surface. The coldest water is found moving towards the top of the lake until it reaches the freezing point of 32 degrees F. or 0 degress C. and forms the protective layer of ice. So, during the winter the warmest water in the lake is found at the bottom of the lake at a temperature of 39 degrees F.

During the fall turnover the lake is being prepared to survive the long, cold winter. The spring turnover,which is just the reverse process, on the other hand, is nature's way of rejuvenating the lake in preparation for all the upcoming spring and summer activity.

One last point before signing off. Not all lakes undergo stratification. Large bowl shaped lakes have more of a tendency to stratify. Large shallow lakes, however, usually do not undergo lake stratification (layering).

Cisco, not trying to offend, just trying to clarify. Have a good day and the spring turnover will soon be at hand.

Remember to always keep your eyes open and your feet dry.

S.v.m