Water Temperatures

nottskev

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Now that we've got rid of that unbearable summer heat (shame!) and the water will soon be cooling down, I'm wondering what use people make of water temperature measurement.

Do you use a thermometer? If so, which one? How do you use it, what does it tell you, and how has taking the temperature helped your fishing? Does it affect what species you fish for, where you expect to find them, or the methods you use to catch them?

I fish through the colder months, but have just relied on intuition and experience, so I'm interested to know what, if anything, might be gained by getting a thermometer out, or rather, in.
 

Keith M

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Back in the mid 70s a mate and I used to do a lot of Barbel, Chub and Pike fishing during the year, and we used to keep detailed fishing logs containing Air & Water temperatures, Wind strengths & directions, Air pressures (together with the pressure trend), weather conditions and even cloud types and cloud coverage.

This sounds a bit over the top but as we were both working as Meteorologists in the Met office at Northwood (HMS Warrior) at this time we had most of this data at our disposal anyway, and we just did it as an experiment to look for any weather conditions that might influence our catch rates.

There were no surprises just confirmations to what we had thought already which basically was:

If the air pressure had been steady for a day or two, or had been falling after a steady period then we would be expecting more bites than usual; as long as there wasn’t too much precipitation.

If the water and the the air temperature had been steady or had started to rise then this also gave us more confidence of having a good day or good nights fishing.

However; as most anglers know already; the more that water warms up then the less oxygen it will hold, and in oxygen depleted very warm conditions it’s less likely that the fish would be feeding much anyway.

The old adage that when the wind is from the east the fish bite the least and if it’s from the west the fish bite the best was also usually quite true too.

The above didn’t always ring true as there were often other things that would influence our results like days when rain would run off of the roads into the streams & rivers or snow melt ran into them and put all the fish off feeding, or the water levels gushing through after stormy periods bringing all sorts of things floating through our swims, but generally overall the above was usually correct more times than not.

Although I still occasionally look at weather charts before I go fishing I only tend to go fishing when conditions look right to me and as I’m now retired I can go any time I want and at a moments notice as long as her indoors gives her permission and if she is a bit stormy or particularly cold I just sneak out anyway :):wh

Keith
 
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peterjg

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I use a water thermometer a lot especially in the colder months.

In summer if the wt is too hot I fish faster more oxygenated water.

In winter if the wt is below 42F it's usually harder. Even if the wt is cold but rising that can be good but a reasonable wt that is falling can be bad.

If below 42F I should really be sensible and fish for chub, grayling or pike but usually I still try for roach.

What is surprising and very noticeable when measuring wt is that nearby different venues of a similar depth can be so different and this can hugely effect catches. For instance; in winter the K&A canal might be only 40F but the very nearby river Kennet could be 4F warmer!!!

I use a homemade water thermometer made from an aquariam thermometer mounted in a bit of plastic conduit with a slot cut into it to read the temperature, it is weighed to sink and is on a length of cord.
 
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daniel121

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As with Keith I use to cheap pretty in death records of water temperatures wind directions. I also used to have some rules for different spices and additives that I could use in certain conditions.

I really don't know if it's just age but now days I can't really be bothered, I just go when I think the weather is going to be the best or when I'm feeling my best. To be honest while I too try catch well, if I don't I don't. I don't over the worry at all
 

no-one in particular

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Aquarian thermometer set up the same as Peterjg. Fished logged into ranges on excel, 31-35f 36-40f 41-45f 46-50f 51-55f 56-60f 61-65f 66-69f 70+f. A few intersting graphs emerged for different species and general data like, the difference in fishing between the 51-55 and the 56-60 range. However, I think one aspect of conditions is not a big deal to make decisions, so many other factors to consider. I digitalised it all on an excel program to weigh it all up in one go which is on a website https://fishingweathergb.yolasite.com/. It was always more about what will be feeding than should I go fishing or not. I don't do it any more, I was on a mission back then plus I dont coarse fish so much but it was an interesting excercise and I did learn a lot.
 
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108831

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The trouble is fish don't read the gen and it's only averages,I've caught big barbel in high pressure along with freezing temperatures and bright sunshine,you can't catch them in your living room and to talk yourself out of success is pointless,just go enjoy a day by the river,take the blank,if it comes,enjoy the success if your that lucky,on one of the venues Keith barbel fishes I regularly caught several barbel on maggot feeder in absolutely terrible conditions,an exceptional venue mind,but worth spending a day nonetheless...
 

theartist

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When Barbel fishing got big wasn't there a set temperature that they 'supposedly' wouldn't feed at? I don't know if those who advocated it were living a self fulfilling prophecy by doing so but it seemed counter productive to use water temps as gospel rather than a guide.
 

108831

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It's total bullshine too Rob,I've stood behind Keith Speers when he'd landed two big barbel,biggest 16lbs on the float in freezing conditions in January,another mate of mine had one 13lber and two fourteens in ice cold water,also on the float in february,that's success in summer,let alone in winter...
 

steve2

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When I had my big fish or bust hat on I use to take careful note of the weather and fish the waters I thought were best at the time. Many times it proved wrong and fish were being caught from the waters I had turned my back on.
Fish it appears don’t play by the rules.
Remember the old days when carp couldn’t be caught in the winter, it was simply because very few fished for them in cold weather. Because they had been told carp don't feed in cold water.
 

theartist

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It's total bullshine too Rob,I've stood behind Keith Speers when he'd landed two big barbel,biggest 16lbs on the float in freezing conditions in January,another mate of mine had one 13lber and two fourteens in ice cold water,also on the float in february,that's success in summer,let alone in winter...

I know, My PB came from a frozen Ivel and I'm still trying to catch a proper snow barbel - the irony is it isn't the water temps holding me back it's the lack of snow and the fact everyone else has the same idea and some places get rammed.

Carp feed ok too as mentioned but is there something to the Tench theory that they can go dormant?
 

108831

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I've caught 6 barbel at Marford in the snow,had a few off the Ivel,D.Stour,nobody knows when I'm going to be hungry,why should a barbel be different,also minnows don't feed when it's really cold,so it's big fish or bust...
 

theartist

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I've caught 6 barbel at Marford in the snow,had a few off the Ivel,D.Stour,nobody knows when I'm going to be hungry,why should a barbel be different,also minnows don't feed when it's really cold,so it's big fish or bust...

When the F*&* did you find all the snow? Did you fish them all on the same day? :D
 
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nottskev

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nobody knows when I'm going to be hungry,why should a barbel be different?

One possible reason is that, unlike a barbel, you don't take your body temperature from the surrounding water...... but I take your point that fish can surprise us when they choose to feed.
 
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108831

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No,but I am an old duffer,and snow only puts me off when it's first fallen,when driving is dodgy,we have snow every year don't forget,my back doesn't after I clear the beggars round my house....Also I haven't been a member of Verulam for quite a few years as the rat race got to much for me.
 

theartist

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Prior to the last few winters It hadn't snowed round here for a couple of decades. I think water temps can actually be decent during the snow before the melt. I remember days fishing the Gade as a lad when it was inches deep yet felt really warm, I wish I took more photos that's for sure, Hate driving in it too, mainly because everything gets gridlocked.
 

peterjg

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For a couple of years I was also a member of Verulam. Marford short walk section was the nearest I have ever seen to a river commercial - it was horrible - most times you could not help but catch! Once I was so fed up catching barbel I moved swims, legered a single grain of hemp in desparation to get away from them and immediately had yet another barbel!
 

barbelboi

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In rivers I believe that the temperature of 39.2F seems to be critical. At this temperature, water is at it's heaviest, and a very small change from this figure can back a lot of difference to what fish will do. I.e. A good angler could catch fish at 40f but at 39, or below, it would more likely be a blank.....................unless it had stayed at 39 for a few days...
 
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Keith M

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When someone states that it’s a load of cr@p because they’ve caught Barbel in freezing cold weather themselves, I don’t think it’s quite as simple as that; we also caught Barbel in the snow on a couple of occasions, and I think that it’s not the cold that prevents them from feeding at all.

Our results seemed to indicate that It was the overall ‘temperature trend’ over a couple of days (or more) and not necessarily the temperature on the day that made the difference.

If the temperature had been fairly steady for a day or two or had begun to rise very slightly after a steady period, even when temperatures were near zero, then the Barbel would often tend to feed. Maybe not as much as during the summer and autumn periods but they could still be caught with snow on the ground and in extremely low temperatures.

But whenever the temperature began to drop steadily it was nearly always the kiss of death for us.

NB: Our experimental data was done on the river Kennet back in those days, and not on the Lea at Marford Farm where they are often queuing up to take our baits :).

Keith
 
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108831

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I didn't say it was cr@p,but it isn't something that is written in stone either,so until it is I will continue to fish and take my chances,blanks happen in perfect conditions,where is the science in that,in good swims where you know fish are,fish aren't going to feed as well in cold conditions,that is obvious,do they shut their mouths totally,absolutely not,scientific study is not absolute proof,as we see every week on the TV....
 
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