Great question. This is actually one of the most frequently asked questions that I get. Unfortunately, there isn't a "one size fits all" answer to this question because it's so dependent on what fish you're chasing and where you're fishing. For example, if you plan to target steelhead trout or Atlantic salmon, you would be better off with a 6 or 7 weight fly rod with an extra stiff backbone and fast taper specifically designed to deal with heavy currents and big fish. However, if your goal was river fishing for smaller trout like rainbow trout or browns, then a 5 or 6 weight fly rod should be sufficient. Lastly, if you are fishing small streams, a 3 or 4 weight is usually my go to. Check out The Best Beginner Fly Fishing Rod And Reel Combos (2021) if you are just getting into fly fishing. This post post also has a link to a book I highly recommend to people just getting into fly fishing or just wanting to improve in general. What is the best time to go fly fishing? Quora Answers - Rhiz Outdoors