# Is it possible to measure water temp in lakes?



## BNicollCSU

I was wondering if anybody could tell me if there is a way to find out what the water temperature is at different depths in a lake at any given time. Is there a special thermometer for this? Or a method that can be used with a thermometer?

I was also wondering if anybody knows of some mathematical formula for figuring out water temperature at various depths depending on surface temperature. For example, if you know that the water temperature within 5 feet of the surface, is there some formula for knowing what the water temperature is at 50 feet? 

If not, what is the method for figuring out where fish are suspended within a water column? Without using a fish finder, that is.

Thank you!


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## CarnageProductions13

Like sitting at home? No I don't believe so. Just the buoys but that's surface temp.


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## EdB

The Ludington weather bouy, when working, show down temps.

http://uglos.engin.umich.edu/station_page.php?station=45024


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## Shoeman

That's tough without a probe, although I remember a thermometer that was in a tube and when when deployed would show temp at a given depth. The pressure of the water was supposed to fill it to a certain level.

I had one back in 70's and it really never worked quite right. (the depth part). I ended up marking a string...lol

Most of your modern graphs (even the entry level ones) will show the thermocline when the sensitivity is set high enough. It won't give you temp, just the break. Basically all you need


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## SalmonBum

I have a manual fish hawk. Its a probe on a cable that you attach to your rigger and lower. Stop at a certain depth and flick the switch. Repeat as needed. I dont use it anymore, as I know that temp dont mean anything. I have caught plenty of big kinds in 70° water. Bait is more important. I will sell the probe if you want. Its just collecting dust.


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## catfishhoge

I believe Fish Hawk now makes a Temp Probe not much bigger than a cell phone. Hook it to a weighted line and drop it to the bottom. Automaticly reads temp in 5 foot increments (I think). Pull it up and you can scroll thru and see your temps.


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## GuppyII

Fish hawk makes a probe that you can clip to a fishing line and with some weight send to the bottom, as you reel it up it gives you temp at five foot increments. There used to be a product called a ' fish finder' that was sold at cabelas that did the same. There is no formula as water has current and temps stratify at different levels. You can have 70 degrees to 80fow then hit the thermocline and in five feet drop to 50 degrees. Good luck.

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## Ralph Smith

CarnageProductions13 said:


> Like sitting at home? No I don't believe so. Just the buoys but that's surface temp.


Here's some at certain bouys.......http://www.glerl.noaa.gov/res/glcfs/glcfs.php?lake=m&ext=vwt&type=N&hr=00...Go under the click down arrow and look at "temp transects" and "temp profile" for the great lake you want to see.


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## BNicollCSU

Thanks for all the info! I've never heard of the thermocline. What is it exactly. 

The reason I was asking about a formula is that I used to take recreational flight lessons, and I remember a general rule about the air tempurature dropping like one degree per thousand feet or so. I thought maybe there was a similar phenomenon in water. 

The reason I'm asking for this information is that I would like to try fishing some inland lakes that are deep enough for trout. I would like to know how to figure out what depth the water becomes cold enough for the trout to be comfortable on a hot day. I'm thinking of a lake that reaches depths of 80 to 100 ft.


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## thousandcasts

BNicollCSU said:


> Thanks for all the info! I've never heard of the thermocline. What is it exactly.
> 
> The reason I was asking about a formula is that I used to take recreational flight lessons, and I remember a general rule about the air tempurature dropping like one degree per thousand feet or so. I thought maybe there was a similar phenomenon in water.
> 
> The reason I'm asking for this information is that I would like to try fishing some inland lakes that are deep enough for trout. I would like to know how to figure out what depth the water becomes cold enough for the trout to be comfortable on a hot day. I'm thinking of a lake that reaches depths of 80 to 100 ft.


Have you ever been out on a lake and jumped out of boat on a hot day? When you jump in, the water is warm and then all of a sudden your feet hit a spot where it's cold. That's a thermocline--the barrier where warm and colder meet. Bait fish cruise the warm water and the predators like salmon cruise the colder part. Finding that thermal barrier is key when trolling for kings. 

One day it could be 50' down, the next day it could be 35' down--depends on the wind and lake currents.


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## mdj

See link below. I bought one this year, not wanting to invest $600+ for the x4 unit being a weekender like I am on the south end. It has proven very useful to me and works as advertised.
http://www.fishhawkelectronics.com/shop/category/handheld-temp-meter/


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## IN-HEAVY

If you have good electronics you can turn up the sensitivity or the gain and the thermocline will show up or and i tell guys this all the time the graph does not lie if your marking fish over deep water in a inland lake just set up above them a little.


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## adam bomb

Youll need a temp probe for that as it is constantly changing with wind, weather currents etc. Many different probes on the market....Fish Hawk, Moor Sub Troll, Cannon Speed and Temp, Depth Raider....Range in price from 300-650


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