[FlyDog]

With the season opening in a couple of weeks I took a drive up to the upper reachs if the N. Fork Yuba in N. Ca. to scout some spots to get back to before the summer onslought. I was checking water temps. as I went and it went from around 38 to 42 degree F. I know the optimal temp. for trout is up around 50 so I'm wondering if I would be just practicing to be fishing these waters at temps listed. I'll probably be fishing nymphs for the most part.
Thanks,

[Greenwood]

My experience this winter (I fish in PA) has been that when water temps were in the 37-39 degree area, the best I could hope for was to pick up the odd fish on small pheasant tails fished slow and deep. At the upper end of your range 42 degrees, they got a little more active although it was still a slow presentation. But, at least you didn't seem to have to bounce the nymph off of their head to get them to eat it. I recorded water temps specifically to get an idea about this.These were smaller freestone and limestone streams.

[tie one on]

In Michigan I've been in water just barely above 32 degrees
with the air temp down around zero & still caught fish. The
biggest problem with fishing in those temps is the ice on the
guides. There have been several threads on what to use to
keep them ice free, but I prefer the "hand breakoff method."

Anyway as long as you are wearing the proper clothing, etc.
temps may not matter. If you don't feel comfortable going out
into those temps, don't. Falling into 32 degree water can put a
slight chill to the bones. It's like so many other things related
to this sport, it's personal preference.

Tie One On

[MTskibum]

I fished threw the winter in montana, and it was a cold winter. I had better luck on bigger stuff, the bigger the better. Although maybe i noticed that because thats what i threw, but i believe i am more likely to get a sluggish fish to move if i make it worth its while. I could be wrong.

Whatever you decide to use, its possible to catch fish in that water temp, although prepare for a skunk as well.

[FISHN50]

Small nymphs fished slow on the bottom works. I use a lot of shot so when the shot hits them they go "oof " & the fly follows right into their open mouth.
Most important is to have a wading staff & wade carefully or you'll have "crinkle clothes" buy time you get back to car.....

[Joni]

I fish the rocky mountain rivers year round. In the winter, I will say Smaller the better. In Drys and Nymphs. We are using 22 to 32 all winter and even right now. Streamers I am not the aquatinted with so the others can answer that. Look at the bugs, you will see they are very tiny right now. Gnats!
The river last Saturday we used #22 and #24 in nymphs.

[FlyDog]

Thanks for the replies...
The only insect life I saw was on the underside of submerged stones. They looked to me like what would be a 14 or 16 prince nymph and some other itty bitty guys that were doing a lot more scurrying around than the other larger insect. Not sure what they were but definitly in the 22 and smaller range.
This section of river doesn't open till 4-26 so I wasn't doing any fishing, just looking for spots to head back to when it does open. Still plenty of snow on the ground but the daytime temps. are definitly warming up.
As this will be my first season fly fishing I'm sure I'll have plenty of days getting skunked but I at least want to feel I'm on the right track.
Thanks again,

[MBWCC]

I fished the Blue River and the Colorado River this winter during February, March, and the first week of April. On all occassions the water temperature was ~36 °F and the air temperatures ranged from the mid-20's to just above freezing. I had no problems connecting with many, many fish on any day. In all cases the flies were very small nymphs (~#22) fished on the bottom.

Here are photos from the most recent trip (photos from April 7, 2008):





The gentleman in both photos, BTW, is Billy Berger of Breckenridge Outfitters, Orvis Guide of the Year 2005 (IRC).

[HuronRiverDan]

I would be looking at small (14 & 16) black and brown stonefly nymphs. It always amazes me when I see them crawling around on a snowbank along side the river.

Dan