Summer Heat & Water Temperatures

[tomitrout]

How did you calibrate it?

Pour yourself a nice glass of ice water, plenty of ice. Let it sit for a little bit, then check it with your thermometer, it should read 32deg.

 

[JackM]

Unless all the water freezes, it should not read 32 degrees. Maybe 33-36. Bureau of weights and measures or two or three other thermometers should get you close enough.

If there is anyone here who has an absolute temp at which they will not fish, please step forward. When I say absolute, I mean, even if you travel all day for a 5 day trip. Otherwise, consider fishing early in the AM, or very late at night, or cancel the trip altogether.

 

[PatrickC]

JackM wrote:
Just to be germane...

How come no one ever wants to be Tito? :-D

 

[tomitrout]

Unless all the water freezes, it should not read 32 degrees. Maybe 33-36.

Or maybe it should....

Here's an official procedure, in case a trout stream thermo really needs to be that accurate...

Calibration in Ice Water


1.Add crushed ice and distilled water to a clean container to form a watery slush.

2.Place thermometer probe into slush for at least one minute taking care to not let the probe contact the container.

3.If the thermometer does not read between 30° and 34° F adjust to 32° F. Non-adjustable thermometers should be removed from use until they have been professionally serviced.

 

[troutbert]

I did the ice water calibration on my fly shop thermometer and it was dead on at 32F.

If you put ice in a glass and add tap water, it takes a while for the temperature of the tap water to get down there. So be patient and let it set for awhile.

 

[troutbert]

Several times I've taken water temps and fishing buddies have taken temps at the same time, both with fly shop thermometers. Sometimes the results matched up, other times they varied by 1 or 2 degrees.

 

[Chaz]

DanVerona wrote:
Sorry for the newbie question but how long do you need to hold one of the thermometers in the water? Should I leave for 30 seconds? A minute?

I bought one similar to the Orvis one posted, but off-brand..

Thanks!

wgmiller wrote:
$11.95 and one of the most functional tools I own... A stream thermometer is cheap and a good way to make sure you're fishing water that isn't too warm!

http://www.orvis.com/store/product.aspx?pf_id=1104

I leave mine in a stream long enough to get what I feel is an accurate reading, probably a minute, then give it a shake and leave it in the water probably another 30 seconds.

 

[k-bob]

Fished a tiny clear NEPA brookie stream, good temps, about 60 late pm today. But another one with swampy headwaters was 68.

I use a wm Joseph infrared thermometer. Expensive but fast and less likely to lose it, since you never put it down.

 

[Mountainbrookie]

The_Sasquatch wrote:
I just have a glass one. Comes in a little crafty black tube. I think it cost me $6.00.

If I buy a fancy shmancy $12 one, I'll lose it.

I purchased one of these from Cabela's and it doesn't seem to take very accurate readings, in fact I'd go so far as to call it horrible.

It's probably a good idea to test any thermometer you buy with the ice water method before trusting it to take accurate temperature readings, especially the cheap ones.

 

[franklin]

k-bob wrote:
Fished a tiny clear NEPA brookie stream, good temps, about 60 late pm today. But another one with swampy headwaters was 68.

I use a wm Joseph infrared thermometer. Expensive but fast and less likely to lose it, since you never put it down.

I have the same infrared one and a submersible digital thermometer. I found that many times the infrared one is measuring surface temps that can be considerably warmer than sub-surface water. As you would expect the fast water gets mixed and the surface temps are more consistent with the overall water temp and on pools the surface and sub-surface can vary by a good bit.

 

[PennypackFlyer]

I'm probably missing some fishing with my attitude that when the water and air are to hot to wear waders it's to hot to fish for trout.

 

[pcray1231]

It's merely the season to focus on smaller, colder streams. June and July are the best fishing months of the year, IMO. The way things are shaping up this year could be just as good in August as well.

I do the big stream hatch chasing thing like everyone else, and enjoy it. But I enjoy a day on those little streams more than anything, and tis the season. Hence why IMO, June/July > April/May. Because the fishing on those streams is better.

And the air temperature isn't so bad when you're standing in 55 degree water.

 

[pcray1231]

Unless all the water freezes, it should not read 32 degrees. Maybe 33-36.

Someone needs an update on chemistry/physics!!!!

If ice is stable in the water, it's at 32.

 

[k-bob]

Franklin, good point that the infrared thermometer is taking a surface water temperature and it would sometimes be colder below the surface ....

 

[Foxgap239]

I will say this about that. I got a reading with my IR on Sat (while fishing for foreign trout) that seemed too high for me so I took my regular thermometer and held it underwater and got a reading 1 degree different than the IR. Not a scientific survey by any stretch but my two cents.

 

[PatrickC]

pcray1231 wrote:

Unless all the water freezes, it should not read 32 degrees. Maybe 33-36.

Someone needs an update on chemistry/physics!!!!

If ice is stable in the water, it's at 32.

And under certain conditions might actually be colder than 32F ;-) Add a little acetone and it can be dang cold and still be liquid. Ok, don't do that, but you get the point. :-D

 

[PatrickC]

PennypackFlyer wrote:
I'm probably missing some fishing with my attitude that when the water and air are to hot to wear waders it's to hot to fish for trout.

It's just the conservative end of the spectrum of attitude on the topic and you certainly won't harm any fish that way. Our lone awesome trout stream in OH stays below 60F (in the upper 3rd of the river) all the way through Summer. Nothing better than wet wading that stream on a 90F day in July. Now, the fishing sucks during the day on those days, but man does it feel good. I waste my time fishing hoppers for dinks on those days during the day. The monster come out at dark ;-) As Pcray said, you PA boys have some nice cold small streams that fish pretty well in Summer. So jealous of that!!!

 

[nymphingmaniac]

http://www.globalindustrial.com/p/foodservice/handling/timing-temperature/cdn-proaccurate-insta-read-cooking-thermometer?utm_source=google_pr&utm_medium=cpc&utm_campaign=Timing-and-Temperature-google_pr&infoParam.campaignId=T9F&gclid=CN73mO6dj7gCFQug4AodcxQAMQ


Just have to calibrate once a year. I have access to highly accurate tempearture baths in the lab. I calibrate with that.
you can get similar items at walmart or home stores

 

[wildtrout2]

I use one of those fishpond thermos, they're a bit pricey, but are accurate. It seems to me that if a thermo gives you an accurate air temp, wouldn't it have to give an accurate water temp? Pat?

 

[DGC]

I would feel lost without a thermometer much of the time, and not just as a matter of avoiding heat stressed fish.

Water temps going up or down in trend; temps of at least 50F for certain hatches during Spring, or for a certain consecutive number of days; different parts of the same stream with surprisingly large differences in temperatures, etc.

Hook and Hackle sold a look-alike to this one shown in Lefty Kreh's book for $2.50 so I bought a half dozen or so. But it no longer seems to be made so maybe it was Mercury based. Anyway, very light and compact if you can find it and reads very fast.

Lefty Kreh Thermometer, page 51 of 101 Fly Fishing Tips