What Water Temperature is Best for Fly Fishing?

To be honest, this is a loaded question. It really has a lot to do with the species of fish as well as the overall profile of the river. You will see a lot of charts out there that state activity ranges and align that information with the types of flies that you should be using. For the most part, I find these charts to be simple guidelines at best rather than fact.

What is most important to remember is that feeding activity is really triggered by the rise or fall of water temperatures. There will be days that you fish a stream at 63 degrees and are able to catch trout with ease. Other days, you will fish that same stretch of water at the same temperature and get skunked. You should really think about what the temperature is expected to be once you arrive. Morning fishing will often produce well as the rising sun will inevitably increase the water temperature. Likewise, evening fishing will produce due to the drop in temperature. I don’t know about the rest of you, but I have been told for many years that the best fishing is either in the morning or in the evening and this was long before I started fly fishing. Maybe that old coot that taught me how to fish in the first place was on to something.

I recommend taking temperature readings as soon as you arrive and compare that result with the forecasted weather conditions of the area. This will be your best guide when attempting to determine if feeding activity will increase. If fishing is slow, switch to a nymphing rig as this will readily reach those trout at the bottom that may be willing to feed given the right opportunity.