Iowa Fly Fishing Hatch Chart
Interactive fly fishing hatch chart for Iowa. See which mayflies, caddisflies, stoneflies, and midges are hatching each month and get fly pattern recommendations. Based on 10 years of scientific observation data (2015–2024).
Using the Iowa hatch chart
This statewide chart compares when aquatic insect observations have been recorded in Iowa. Select a month to compare the share of annual mayfly, caddisfly, stonefly, and midge observations, then review fly patterns commonly used to imitate those insect groups.
Our Iowa hatch chart is built from 10 years of scientific observation data (2015–2024), covering the major aquatic insect orders: Ephemeroptera (mayflies), Trichoptera (caddisflies), Plecoptera (stoneflies), and Diptera (midges). Use it to plan your fishing trips around the most productive emergence windows of the season. Actual timing varies with elevation, latitude, water temperature, and seasonal weather, so confirm current activity with local reports and on-water observation.