As long as there is open water, there are great opportunities for fly fishing to be found. Fly fishing in May can be great as this period is the transition from spring to summer. The continuing warm-up means changing conditions and fish patterns.
For example, in addition to potential periods of rain, fly fishing in Montana in May or fly fishing in Wyoming in May can be rewarding, but runoff from snowmelt can complicate things. Anglers may need to be flexible and able to “pivot” when chasing brown trout, rainbow trout, or native cutthroats in mountain streams and perhaps consider alternative streams. Presenting larger and/or dark flies can help with possible decreased trout visibility from higher water, off-color conditions. If fly fishing in Colorado in May, or any of the other western mountain region states, you also may be able to find fly fishing opportunities in upper elevation lakes which do not experience the same dramatic fluctuation in water level.
For many anglers, warming water helps create the best fly fishing in May. Fish metabolism increases and they can become extremely hungry. The bite changes from a cold-water reaction hit when something comes near, to actually wanting to eat and chasing bait and hopefully, flies. Insect hatches continue to increase, triggering feeding frenzies for fly anglers that are mindful of timing. Also in May, aquatic vegetation is starting to grow but rarely achieve the level of becoming a fly fishing obstacle.
Additionally, some of the best fly fishing in May can be attributed to spawning activity. This shallow concentration of fish plays right into the hands of fly anglers targeting crappie, bass, and even carp. Sunfish spawning areas can be a great place to gain confidence with techniques and fly experimentation when fly fishing in May. Heavier flies and clear water can help with the timing of the hookset.
When fly fishing in May, you may notice less fishing pressure. Summer vacations have yet to start and although the water is warming, it may not yet be warm enough for many traditional anglers. Fly anglers usually are active earlier in the year to take advantage of the cooler water to chase trout. In some states, such as Pennsylvania, May can mean a second trout stocking that often is overlooked by many anglers so be sure to check your state regulations booklet or website.