Water temp variations on the lake

[EastMarkME]

So I know that water temp matters. I check it when I go out and as most have general rules of thumb where to start lure and presentation type/speed based on temp/season.

My question is does it matter in general to keep in contact continually with specific temps throughout the lake as you fish ?

Does it always or ever payoff to pay attention to the varying temp in terms of figuring out patterns ?

Is it more theory or rarely a help or is it a practical daily practice for you guys that really helps ?  Its 68 here and next spot 70...do I need to care?

Thanks for any insight guys.

Mark

[Fishing Rhino]

Hmmmm, good question.  I'm not sure.  Whatever is working is what I use.  I don't change because the surface water temp varies.  The sheltered sunny side of a pond will always have higher surface temps than the opposite side where there is shade, and the wind stirs the surface and the cooler subsurface water, giving cooler temps on the surface.

I'm looking forward to the answers from those in the know.  

[Skinnyh2ofishin]

Just remember if you're using a standard sonar temperature reading, it is taking the temperature of the surface of the water.  This doesn't correspond to the temperature that the bass are holding at since the temp drops throughout the water column and not always evenly.  The surface temp also rises faster throughout the day, whereas deeper water isn't affected as much by the sun.  Bass in very shallow water are going to be affected more by temperature variation throughout the day than bass in deeper water.

Overall, temperature is merely one of the factors to my overall fishing plan, but I don't search for areas where the temp is the same as where I was just catching fish.  If it's winter and the water is cold, I may fish areas of the lake that I know get more sun exposure and will warm up faster.  Basically, to answer your question I use average water temperature as a planning factor before my trip, but I'm not fixated on small changes in temperature throughout the day on the lake.  

[tnhiker44]

I certainly am no expert, but in my experience a few degrees one way or another has not made a big difference. Especially right now, where I have seen temperatures as low as 85 degrees and as high as 94 degrees. I am pretty sure in the transitional periods temperature plays a much bigger role, but I have never discovered a magic temperature number.

[Wayne P.]

During late Winter to pre-spawn, I specifically pay attention to the surface water temp. Anytime the air temp is a few degrees warmer than the water temp, I check the downwind shorelines to verify that the water is warmer than the rest of the lake, and it usually is. On calm sunny days with the air temp close to the water temp, I check the shoreline areas with the most direct sunshine for warmer water temps and it usually is. During the spawn, I look for the water temp suitable for the spawn that may have been affected by a severe cold front or a cold rain. Post spawn until the Fall cool down, water temp is important to finding bass relating to the thermocline. Other than those senarios, the water temp doesn't seem to matter as much.

[FD.]

68 to 70 degrees, I pay no attention to.

But in March the difference between 58 and 61 is huge.   In August the difference between 88 and 91 is noticeable.  Anywhere in between 65 and 85 does not seem to make a difference.

[EastMarkME]

I'll tell you the 'rest of the story' as Paul Harvey would say. I recently got a seperate Humminbird that reads temp among other things in the front of boat finally.

The tranducer cable on this wireless MG trolling motor I have is a PIA due to the way the motor stores. The cables in the way all the time or getting pinched.

They make a built in transducer option I can add but the transducer is Lowrance and I will loose my temp capibility cuz mines a Humminbird.

The cable runs inside the tube on that setup which is awesome. I will still have the fishfinder/GPS which is what I use most anyway.

So I guess Im wondering if I'll be hindering my fishing much to loose the temp. I still have the handheld digital probe I can check with when I first get out to get an idea of general temp.

Some good responses so far. Thanks for them. Im learnin....

Mark

[WRB]

Summer period water temperature is extremely important. The surface emperature isn't important, the bass don't live on the surface.

Lakes in the summer layer into water that can support bass and water that can't. The upper layer of water that supports bass cools as it gets deeper and at a depth where the water temperature changes rapidly within a few feet is called the thermocline. Think of a layer of a sheet of plastic, below it they can't. If you are fishing below the thermocline layer, no bass will be at the depth.

The summer thermocline makes finding bass easy. Determine where the thermocline layer is and fish at or above that depth. The ideal depth changes during the day due to wind bending the thermocline and early or late in the day the thermocline tends to rise a few feet.

WRB

[EastMarkME]

Summer period water temperature is extremely important. The surface emperature isn't important, the bass don't live on the surface.

Lakes in the summer layer into water that can support bass and water that can't. The upper layer of water that supports bass cools as it gets deeper and at a depth where the water temperature changes rapidly within a few feet is called the thermocline. Think of a layer of a sheet of plastic, below it they can't. If you are fishing below the thermocline layer, no bass will be at the depth.

The summer thermocline makes finding bass easy. Determine where the thermocline layer is and fish at or above that depth. The ideal depth changes during the day due to wind bending the thermocline and early or late in the day the thermocline tends to rise a few feet.

WRB

Wow. That is great info WRB. I knew temp mattered but wasnt sure what the surface temp told me. How do you determine where the thermocline is and is it something you use often as a locating tactic ?

Mark

[EastMarkME]

Just remember if you're using a standard sonar temperature reading, it is taking the temperature of the surface of the water. This doesn't correspond to the temperature that the bass are holding at since the temp drops throughout the water column and not always evenly. The surface temp also rises faster throughout the day, whereas deeper water isn't affected as much by the sun. Bass in very shallow water are going to be affected more by temperature variation throughout the day than bass in deeper water.

Overall, temperature is merely one of the factors to my overall fishing plan, but I don't search for areas where the temp is the same as where I was just catching fish. If it's winter and the water is cold, I may fish areas of the lake that I know get more sun exposure and will warm up faster. Basically, to answer your question I use average water temperature as a planning factor before my trip, but I'm not fixated on small changes in temperature throughout the day on the lake.

Another great response. I appreciate all you guys sharing the knowledge regardless of topic. You wonder sometimes when you read an article if it slanted by a desire to sell a product. These replys are real and practical responses which is priceless.

Mark

[WRB]

Most bass fisherman start to fish in the spring and stop in the fall, a few fish year around. This is due to regional location and commitment to other sporting activities.

The bass however live year around in the same lake, river or pond and locate where ever they can survive; food, shelter and comfort.

The only seasonal time that changes those factors is during the spawn when food, shelter and comfort are not a factor.

Bass being cold blooded animals are affected by the water temperature, water temperature controls nearly everything in the basses life cycle. When the water gets to warm to hold sufficient dissolved oxygen levels, the must find cooler water to breath; the upper temperature limit is around 85 degrees and low DO limit about 3 mg/l.

A good sonar unit can display where the colder more dense water meets the lighter warmer water layer called the thermocline. The layer is displayed as a dark line at one depth or a fuzzy grey zone at one depth, depending on the density of the water change. You can also look for a depth zone where baitfish are suspended, as both bass and baitfish prefer to be near the thermocline, unless moving shallower to feed or escape predators.

In the fall colder surface water mixes with the warmer surface water the result is called a turn over when the low DO water below the thermocline is pushed towards the surface.

Bass fisherman who fish year around learn to adjust to seasonal changes and bass locations.

WRB

[Paul Roberts]

Good stuff here by all, esp Wayne P and WRB.

I take temps religiously, but mostly to better understand how aquatic systems work. I really don't like the feeling of not understanding something.

One thing I would add to what's been said is that, while temp is important to fish and you should get a bead on the real limitations that exist in your waters through the seasons (again WRB and Wayne hit these pretty well), on a short term basis --what we deal with when fishing --it's rare for water temps too change too drastically.

Water both takes on and gives up heat slowly, buffering air (weather) effects. On top of this, bass seem not to respond adversely to temp changes less than say 6 to 8F in the short term -these are very large changes not commonly seen. You are most apt to see such drastic changes in spring and fall, and they affect the shallows mostly. As tnhiker44 said, a few degrees either way just doesn't stop bass from hunting, or at least their willingness to hunt.

So...you could get by pretty well without taking temps. You decide how much you want to know. Just running down what Wayne and WRB introduced is more than most anglers do.

[RoLo]

Since fish are cold-blooded creatures, water temperature has an undeniable bearing on their disposition.

However, it's my believe that fish lack the sensitivity to react to minor temperature change,

which is nature's way of protecting them from reactionary whipsaws caused by every thermal fluctuation.

In my view at least, the TREND of water temperature is far more important than the STATIC numeric value.

When someone informs you of the current water temperature, you haven't learned very much.

Provided you have your own water temperature gauge, if someone informed you instead of the water temperature

two-days ago, you would then know the current trend of water temperature.

In brief, an UPTREND in water temperature is positive, while a DOWNTREND in water temperature is negative.

Dean Rojas set the B.A.S.S. all-time one-day stringer record on Lake Toho, Florida (45 lb, 2 oz).

Dean is an excellent angler, but his stringer-weight got a little help from Mother Nature.

In the days prior to that January tournament, a bitter cold-front sent temperatures tumbling sharply downward.

During that major downtrend in water temperatures, most pro anglers could not buy a bass during practice,

but then the day before the tournament began there was a sudden trend-reversal.

On the heels of the bitter cold-front when bass were fasting, water temperatures suddenly skyrocketed

for the next couple of days. Dean was wise in selecting Shingle Creek where bass were aggregating in current,

but his record-shattering stringer got the mightiest boost from Big Mama (water temperature uptrend).

Roger

[Catt]

Thermocline does not take place in every body of water

Thermocline: a layer of water in an ocean or certain lakes, where the temperature gradient is greater than that of the warmer layer above and the colder layer below. Depending on the geographical location, the thermocline depth ranges from about 50m to 1000m.

Here is a very informative read from a wonderful web site

http://www.bassresource.com/fishing/thermocline.html

[JuniorFisherJJ08]

Ok, here in ohio i fish alot of tournaments and such and have followed these guidlines by doing so. But before i go into detail im going to give you  my perspective on water temps. Fish are like people the older you get the harder it is to stand the heat but a few older fellows can deal with it. The younger you are the eaiser it is to deal with the heat. The same goes for the fish. I fish for my limit on tthe structure i can see be it rocks, weeds or wood. once i have my limit  i move offshore and fish for my kicker fish. Our surface tems run about 78deegrees f. the deepest dropoff ledge ive seen/picked up bass this yearhas been around 14ft.

[Paul Roberts]

Catt wrote:

Thermocline does not take place in every body of water

My guess is it's more a northern phenomenon. In TX it would have to be a pretty deep lake not to heat through. That's a guess since I don't fish and take temps down there.

The thermocline TC gradually gets pushed deeper as upper waters heat. In many (northern) waters you can look for a TC anywhere beyond 15feet and it gets deeper as the summer progresses. I've seen TCs as deep as 120 feet in August. Lakes that get heavily windswept may have the TC break up by mixing.

I fish ponds that are mostly less than 15ft deep so my TCs are gone by the end of June.

JuniorFisher wrote:

Our surface tems run about 78deegrees f. the deepest dropoff ledge I've seen/picked up bass this year has been around 14ft.

You might just be fishing as "deep" as you need to at this point in the year.

[WRB]

Most high land and hill land resevoirs develop a thermocline during the summer. Power gerneration lakes may develop multilple DO rich thermocline layes created by current or water moving through the dam.

Smaller lakes and ponds will develop thermoclines so dense that the DO is completely gone below the layer as decaying vegetation and algae consumes all DO. The upper water looses DO as it warms above 90 degrees and massive fish die off occur, if the lake or pond doesn't have an aeration system or no wind to mix DO.

By using your sonar or from years of experience, you can determine the life zone or preferred depth the bass are using.

Anyone who has ever swam in a lake during the summer can tell that the deeper water is colder than the first few feet of surface water, unless the lake is very shallow.

The topic* was about a disgruntled fisherman fishing deep structured lakes. Deep is always a relative term depending on the lake classification and location.

The thermocline on lake Casitas for example, the time I fished, was between 18 and 28 feet, depending on wind and time of day. You can catch bass at 30 feet when the TC is at 28', but when it bends and raises, you may blank at 25' feet and need to fish shallower. If there is a double thermocline, then the deeper TC works all day.

There is nothing to prevent a bass suspended at 25' for example from swimming up to the surface, the air bladder expansion is well within that range. There is no reason for the bass suspended at 25' to swim deeper into low DO water without prey.

It's hard to fish too shallow, easy to fish too deep, during the summer on deep structured lakes. No thermocline, the bass are not restricted and can go to any depth they choose.

WRB

PS; whoops, wrong thread.

[Catt]

Read the link I posted; clear, precise, and to the point

[EastMarkME]

I am starting to understand the basics of varying water temp/bass thanks to all these great replies.

Good stuff.

Mark

[Matt Fly]

For you guys that don't think your graph displays the thermocline, my old ones didn't either or I didn't properly adjust it back then, but alls I did was drive under the bridges with deep water.

  Bridges always hold fish, and normally, the crappie will show up like stacked cord wood, they are always just above the thermocline with the bait.

  When we didn't own electronics, Dad would put the crappie jig to work around the pilings, catch a few and you would have your depth.   Dad marked his line with marker,   then would take the line and use the boat length as his guide to determine depth.

  Most of the time, I just ask the fishermen that are tied up.