Taking Water Temp: Depth/duration?

[Six-Gun]

I just picked up a thermometer to check the water temps in my local creek. It's a fairly elevated water body (around 6500ft.) and the water is still pretty chilly to the touch, but I still want to know for sure what the temps are along the stream.

That said, how deep and for how long should I be setting this thing in the water for an accurate reading? What's the warmest water you guys will fish for trout? Thanks for your help.

 

[Railking]

Being that the water is moving, the temperature is fairly consistent from surface to bottom. That always seem to be the case for me anyway. Didn't seem to matter if it sat on the bottom or dangled off my wading belt, the temp was pretty consistent. 68 is about the warmest I'll fish for trout. 70* is generally the cutoff for everybody.

 

[Fishidiot]

Six-Gun wrote:

That said, how deep and for how long should I be setting this thing in the water for an accurate reading? What's the warmest water you guys will fish for trout?

Put the thermometer in a shallow section of stream with some current and that is in the shade for 2-3 minutes - this should do it.

For me, catch and release trout fishing stops at about 70 degrees F (a couple degrees cooler on brook trout streams).

 

[Six-Gun]

Thanks for the feedback and info, guys. It will be interesting to see what the actual temps are up there at various point in the creek. All I know is that my hands were starting to sting a bit while releasing a cutty up in the higher sections. Hopefully, there's still plenty of temp to give since this is still about the hottest part of the season up there.

 

[Railking]

Temps in my area are extremely low for August with the cold nights we've had. Trout fishermans dream.

 

[boychick]

Put the thermometer in a shallow section of stream with some current and that is in the shade for 2-3 minutes - this should do it.

There you go.

 

[afishinado]

It really depends on the thermometer itself and also the reading of the thermometer when it's put into the water.

Try this: Put the thermometer in the water for 30 seconds and take a reading. Do the same thing for a minute and see if the reading is different. Try longer. You can get an idea how long it takes for your thermometer to give you the correct reading.

Also, I attach a lanyard to the thermometer and let it hang down into the water. The lanyard prevents loss and you can tie on a fly or do other things while the thermometer is submerged.

 

[Six-Gun]

The lanyard thing definitely caught my attention, as I was trying to figure out the best way to submerge it without having to hold the thing for the entire measurement time. Thanks for the tip on that.

I did a little test with running tap water last night and it seems the thermometer I have needs about 2 - 2.5 minutes to totally settle down. Obviously, that could be different give the water flow of a much larger stream, but it's a starting point.

 

[Chaz]

Tie it on a string and drop it in the water for a minute, that will give you an accurate temperature.

 

[pcray1231]

All I do is wait until I have to do something, like tie on a new tippet section or something. I toss it in a spot, on top of a rock submerged about elbow's length in the shade, so that it's easy to retrieve. I do my business. Afterwards I pick it up and take a reading.

I'm guessing your streams out there are in the 50's. Our smaller waters are always fine. And we're having a great summer, even some of the medium and larger waters are doing fine too.

 

[Six-Gun]

Very good estimate, pcray. I finally got around to fishing my mountain creek spot and applying the advice in this thread. The water temp up there were 52 degrees after a very hot summer, (100+ degrees air temp most days), so it sounds like I've got nothing to worry about year-round at this place. Good to know and a great reference temp to compare with the other areas I fish.

 

[albud1962]

 

[albud1962]

Well the highest point in Pennsylvania is under 3,600 ft MSL, so I am not sure where you are fishing. I use a digital meat thermometer available at Lowes for around 20 bucks and place the probe about 6" into the flow to get an idea of the temps I am fishing. Seems to work well for me.

 

[Six-Gun]

This is mostly in southeastern Utah, primarily on Rocky Mountain freestoners. As I now know, even during 100 degree heat, the mountain runoff keep thing very cool up there.

The digital meat thermometer sounds like a very good idea.