Your Local Stream Temps

[Dave_W]

Swattie87 wrote:
Inthey seem to be very active well up into the 60's, approaching 70 even. Anyone else notice this?

Yes, this does seem to be the case...although I wouldn't say this is a dramatic difference. They also seem more active at the colder end of the spectrum as well, in my experience. Part of this may, however, be a result of browns being more wary and nocturnal, especially in summer.

Nevertheless, I agree the bows seem to be pretty active in some of the larger waterways with warmer temps this time of year.

 

[Dave_W]

This is a good thread. I'm going to try to get some temps today during my travels.

 

[wildtrout2]

fayettenamese wrote:
58-62 seems the best for me

I totally agree with these temps being optimal.

 

[afishinado]

Here is some interesting water temp info for both fish and bugs:

The Water Temperature Game

77°F – Upper limit of Rainbow trout survival

75°F – Temperature at which Rainbow trout stop growing

68°F – Temperature at which anglers should consider not fishing for trout

68°F – Temperature at which Browns and Rainbows start to become stressed

67°F – Temperature at which trout significantly decrease feeding

65°F – Temperature at which Brooks start to become stressed

60°F – Temperature at which Damselflies begin to hatch

59°F – Upper end of optimal fishing temperature for Cutthroat trout

58°F – Optimal temperature for PMD hatches

55°F – Optimal temperature for Quill Gordon, Hendrickson, Salmonfly, Trico, Green Drake and Caddis hatches

54°F – Upper end of optimal Baetis hatch temperatures

50°F – Preferred temperature for Cutthroat trout spawning

50°F – Lower end of optimal temperature for Crayfish activity

46°F – Optimal Brown trout spawning temperature

45°F – Optimal temperature for Chironomid hatches

45°F – Optimal Brook and Cutthroat spawning temperature

44°F – Lower end of optimal fishing temperature for Brooks, Browns, and Rainbows

42°F – Lower end of optimal water temperature for Midge hatches

40°F – Minimal water temperature for Baetis hatches

39°F – Lower end of optimal fishing temperature for Cutthroat trout

33°F – Minimal (not ideal) temperature for Midge hatches

Link to source: https://www.headhuntersflyshop.com/trout-fishing-water-temperature/

 

[jifigz]

Nice list afish! It'd be nice to have upper limit of Brown and Brook trout survival. I personally believe Browns can survive water temps higher than many people give them credit for.

 

[Swattie87]

Dave_W wrote:
This is a good thread. I'm going to try to get some temps today during my travels.

It's 72.3 F in my cubicle today. :hammer:

It was 62 deg on a smallish central PA freestoner on Tuesday though when I played hooky. Air temp was low 70's.

 

[k-bob]

Nice list afish. I try to stop brookie fishing if the temperature hits 65. Might be a little bit on the safe side, since I often fish steep streams that tumble onto rocks and probably churn more oxygen into the water, but that's ok.

 

[TYoung]

The SRBC provides temperature data for many streams in the Susquehanna River watershed.

SRBC Stream Data

 

[Jessed]

I think this year has been incredible compared to last year. I really started getting into trout fishing heavily 2 years ago. Dry and hot summers were not really a factor fishing warm water species, the fishing was still good. The last two years were brutal, we've had more rain and better water levels in the middle of
Summer than all spring last year!

 

[sarce]

Not that it makes a difference as far as fishing for them, but 77 as an upper limit for rainbow survival seems too low. I've caught plenty of holdover rainbows that survived 80 degree range temps. The rest of the numbers seem accurate.

I agree with kbob about brookies and the 65 degree mark - I don't think it would actually harm them if caught a few degrees above that temp, but in my experience brookie fishing is much slower above 65 degrees, and they tend to cluster up in deep pools by this time. You can catch more fish when they are more spread out.

 

[Dave_W]

Trout streams in the Cumberland Valley are in good shape and with good flows lately.

My thermometer got the following today (not a hot day to be sure):

Lower Yellow Breeches: 66 degrees at 11 am.

Lower Letort at Shady Lane: 59 degrees (Letort is reliably cold).

Lower Mountain Creek vicinity Mount Holly Springs: 65 degrees at 2pm.

 

[fayettenamese]

I also believe the rainbow numbers are askew. The fingerling plantings that grow up in the yough almost behave as wild trout. While fishing for smallmouth even down into connellsville, I notice that those fingerling planted rainbows that grew up stay active until about 73 degrees. I know this because I frequently catch them on my SMB offerings. I have seen stressed trout, and these rainbows do not behave as such. As I said in another thread, I believe that the oxygen content from the whitewater areas keeps them safe a few more degrees up in temperature.

 

[salmonoid]

fayettenamese wrote:
I also believe the rainbow numbers are askew. The fingerling plantings that grow up in the yough almost behave as wild trout. While fishing for smallmouth even down into connellsville, I notice that those fingerling planted rainbows that grew up stay active until about 73 degrees. I know this because I frequently catch them on my SMB offerings. I have seen stressed trout, and these rainbows do not behave as such. As I said in another thread, I believe that the oxygen content from the whitewater areas keeps them safe a few more degrees up in temperature.

I think you are spot on. It is not the temperature that kills, but the DO content. The solubility of oxygen decreases as water temperature increases, but if you have a source to aerate the water, your DO concentrations will be higher than the DO in a similar flat stretch of water.

There is much handwringing about fishing in "extreme" water temperatures (whatever that cutoff is - 42 degrees, 65 degrees, 78.9743 degrees). But the experience sarce lists, about fish clustering up in pools when the temperature gets warm, and the fishing slowing, is a built in inhibitor that limits fish mortality, because the fish go into hunker down mode. 99% of the time, they won't chase anything. I used to salivate when I would come up on what I now know is a spring seep, and see dozens of brookies holding, and used to be puzzled why I couldn't catch a single one. I now know why, I know the water was borderline temperature-wise, and I also know I never caught a single one of those fish. Perhaps I was in error being present; my shadow may have cause the already thermally stressed fish additional stress.

 

[jifigz]

I am totally surprised by this but my favorite freestone mountain brookie stream clocked in at 70 F today at about 4 pm. I was downstream a ways because I was just checking it briefly on my way to Huntingdon to sell wine, but I couldn't believe it came in that high. The stream is small, high gradient, and packed with brookies and some occasional wild browns. It is shaded and flows through forests everywhere upstream from where I was. Last year in the super drought and extreme heat it clocked in at 72 F in basically the same location. Crazy. Maybe I should hike up in to where I usually start fishing and take a temp, but I can't imagine it would be that much different. Maybe it would be though, because last year my feet were uncomfortably cold wading it in flip flops after hiking up and hammock camping overnight.

 

[Dave_W]

The southern half of the state received a tremendous amount of rain yesterday afternoon and into the night - 4" in my backyard gage. It was also a fairly cold rain with air temps mostly in the upper 60s. I was also surprised driving around yesterday evening to see the extent of the precip that soaked in rather then running off.

Continued good news for trout streams.

 

[troutbert]

jifigz wrote:
I am totally surprised by this but my favorite freestone mountain brookie stream clocked in at 70 F today at about 4 pm. I was downstream a ways because I was just checking it briefly on my way to Huntingdon to sell wine, but I couldn't believe it came in that high. The stream is small, high gradient, and packed with brookies and some occasional wild browns. It is shaded and flows through forests everywhere upstream from where I was. Last year in the super drought and extreme heat it clocked in at 72 F in basically the same location. Crazy. Maybe I should hike up in to where I usually start fishing and take a temp, but I can't imagine it would be that much different. Maybe it would be though, because last year my feet were uncomfortably cold wading it in flip flops after hiking up and hammock camping overnight.

If you would have checked several miles upstream it probably would have been cooler. That's the usual pattern. The water comes out of the ground at about 50F.

On a day when the air temp is 85F, as the water flows downstream it gradually takes on more heat from contact with the warm air and so its temperature rises. It's pretty straightforward.

Good shade from trees helps reduce the rate at which the water warms up, but it will still warm up.

The water comes out of the ground at about 50F. By the time it reaches Harrisburg it's been flowing a long way, so on a blazing hot day, it can reach 90F above Harrisburg.

 

[jifigz]

I understand all of that Troutbert, but it still shocked me it was that warm there given the weather we've had this year. It sure is a fantastic brookies stream with some decent browns thrown in as well.

On a side note my rain gauge measured 1.9" from that recent event. Certainly not 4" like Dave recorded but it has been a great year with keeping the aquifers supplied around here.

 

[tstooge26]

This has been a very interesting thread, I understand the water temp and I always carry a thermometer but my question is about the dissolved water. Question one, if I'm on a small mountain stream that is relatively steep where the water gets a lot more oxygen would you say it's safer to fish at slightly higher water temps compared to a flatter stream...question 2 has anyone ever carried a DO meter and used that to judge whether it's safe or not to fish...a quick google search came up with many DO meters that aren't terribly expensive and if so what are the DO levels your are looking for, how low is a to low DO level?

Thanks

 

[salmonoid]

6.5mg/L is probably a good cutoff for salmonids. Below that, things get iffy. You can theoretically get higher DO concentrations in water that is highly aerated; the water becomes supersturated above and beyond the normal DO concentration it can hold at a given temperature, but I think that effect is going to be localized. I looked at DO meters a few years back, but they were too salty for me then. Probably should revisit that, as I would love to know what the DO was in a stream I fished today, and how much it varied in different locations.

What DO meters are you finding that aren't expensive? I'm still not finding anything under $100.

 

[tstooge26]

My apologies when I did a quick search I was looking at accessories for the DO meter not the meter itself, I should pay more attention to my search results.

Thanks fir the info on DO levels though