Just like baking a cake, you need all the right ingredients. With the flora the sun warms the soil, and that last ingredient is a warm rain. A rain in the 65 Farenhiet range with its high humidity triggers growth of the leaves, mushrooms, and flowers and thus bug hatches begin on masse. This generally happens at this latitude about mid May. This starts the dry fly season.
If the rivers are within their banks and not silted up, success with surface takes begins. Tannin or tea colored water is of no concern. Experts say the tannin acts as an antiseptic for the trout. It is said to keep in check micro organisms that attack trout. Sounds good, and we'll have to take their word for it. Adams, Stone flies, even Humpy patterns are on the menu. The next 60 days are the brightest days of the year and the longest. Use a 9 foot-5X leader and avoid the bright sun light. It is this time of year that water temperatures reach 58-62 F in the 5-6 PM time frame. Perfect for those of us who have jobs! The warmer periods of mid July that push fly fishing time periods to dawn & dusk are months away.
Your next concern is tracking the different species of bug hatches. That involves knowledge of each species. Litobrancha Recurvata, Hexagenia Limbata and other Genus of the Ephemera. Hahaha...don't panic, it just size and color you need to match. The Latin names? The trout don't know them either!
It is all visual when casting to a trout. The massive Steelhead trout will still disrupt the Great Lakes tributaries until late May, but the upper reaches of many streams are unaffected by them.
Today's fly fishing beginner has access to information that it took 20 years of trial & error for me to learn. One can be a successful player in just a few short years. It is a challenging endeavor, but I have never been bored on a trout river.
"Walk softly and carry a graphite Stick!"