The Best Flies for September Trout Fishing
Cooler mornings. Small mayflies. Hoppers along the banks while warm weather lasts. September bridges late summer and fall, so a useful fly box needs both subtle insect imitations and a few patterns with movement. These 25 trout flies bring together BWO dries, caddis, terrestrials, tungsten nymphs, and compact streamers.
Hatches vary by river, elevation, weather, and water temperature. Use the insects and feeding behavior in front of you to choose a pattern, then adjust its size, depth, and presentation.
Blue-Winged Olives and Fall Mayflies
Blue-winged olives, often called BWOs or Baetis, are a key fall hatch on many trout streams. Watch for small mayflies and steady rises, especially during cloudy weather. The Classic Blue Winged Olive (BWO) is the dedicated dry-fly choice in this collection; the Parachute Adams offers a versatile alternative when other mayflies are on the water.
Before trout begin rising, try the CDC Baetis - Tungsten or Juju baetis below the surface. The CDC Baetis adds soft movement and a tungsten bead for depth; the Juju baetis provides a slim mayfly profile for selective feeders. Match the naturals and aim for a drift without drag.
Add the Flashback Baetis when you want another small mayfly profile below the surface. Fish it before or during local BWO activity, and choose the size that best matches the nymphs trout are eating.
September Caddis: Surface to Subsurface
Caddis can remain important into September where local hatches continue. Fish the Elk Hair Caddis when adults are on the surface or you need a buoyant dry in broken water. Try the X Caddis when fish are taking vulnerable caddis in the surface film.
For subsurface caddis feeding, drift the Holy Grail - Tungsten through riffles and seams. Choose the pattern and size that match the insects you see; larger autumn caddis may call for a different size or silhouette than the smaller caddis in this selection.
The Caddis Larva Perdigon is a compact tungsten option for probing riffles and deeper seams. The Guide's Choice Wet Fly offers an emerging-insect profile; try a dead drift followed by a gentle swing when trout are feeding just below the surface.
Hoppers and Terrestrials Before the Frost
Keep terrestrials handy during warm September afternoons, especially near grassy banks and overhanging vegetation. Their importance usually tapers as cold weather and frost arrive.
The Baby Hopper offers a grasshopper profile, while the Micro Chubby is a visible foam dry for searching bank water or carrying a light dropper. Amy's Ant adds a larger attractor silhouette when you want to change the look. Match the dropper weight to the dry fly's buoyancy and work bank edges with controlled drifts.
Nymphs for Quiet Surface Water
When nothing is rising, start below the surface. The CDC Pheasant Tail - Tungsten offers a natural mayfly profile, and the Olive Quill Perdigon is a slim option for reaching feeding depth in current. Both fit indicator, Euro nymphing, or suitably balanced dry-dropper rigs.
The UV Zebra Midge Perdigon rounds out the smaller subsurface options for tailwaters, spring creeks, and trout feeding on midges. Adjust weight and depth to the run before changing flies; a well-placed drift matters as much as the pattern.
The Gold Ribbed Hare's Ear adds a buggy, general-purpose nymph profile. Try the Purple CDC Hare's Ear - Tungsten for extra movement and a touch of color in deeper water or low light. The Flashback Perdigon gives you a slim, fast-sinking alternative with a subtle flashback.
Stonefly Nymphs for Deeper September Runs
Stonefly nymphs remain a subsurface food source in rivers that support them, even when adults are not hatching. The Black Sparkle Stone - Tungsten offers a dark profile for deep seams and broken current, while the Natural Golden Stone - Tungsten provides a lighter, natural-colored alternative.
Use either as a heavier point fly in a two-nymph rig, with a smaller Baetis or midge pattern behind it. Match the weight to the flow and keep the drift close to the feeding lane.
Small Streamers for Early Fall
Carry moving prey imitations for pools, banks, deeper seams, and periods of low light. The Polar Bugger offers a familiar swimming profile with flash. The Feather Flash Leech provides a compact tungsten-beaded option with soft feather movement.
Try short strips with pauses, a slow retrieve, or a gentle swing. Let the current work the materials and vary the speed until you find a response.
The Feather Flash Minnow adds a small baitfish silhouette for banks, pools, and seams. The Mini Jig Leech gives you a compact jig-style option to dead-drift through deeper runs or retrieve slowly in stillwater. Rotate between these and the Polar Bugger or Feather Flash Leech to vary profile and movement.
What Is the Best Fly for September?
Start with a BWO dry when small mayflies bring trout up, caddis patterns during a local hatch, or a hopper on a warm afternoon near grassy banks. Use mayfly and midge nymphs when fish are feeding below the surface, and try a small streamer when moving prey draws more attention. This September selection gives you 25 options for adapting as late summer turns to fall.
