What Changes for Trout in Autumn
As days shorten and water cools, many trout feed actively to build energy for winter. Some species, such as brown trout and brook trout, spawn in the fall in many regions, which can change both their behavior and how anglers should approach them. Insect activity shifts too: terrestrial insects fade, while small mayflies and some caddis remain.
Timing varies by region and elevation, so check local reports for what is happening on your water. For the wider picture on spawning, flows and bait, see trout fishing in fall.
Blue-Winged Olives
Blue-Winged Olives (BWOs) are small mayflies that often hatch on cool, cloudy or damp days, and fall is a well-known time for them in many rivers. Useful patterns include:
- A BWO nymph or Pheasant Tail Nymph in small sizes.
- A BWO emerger, fished in or just under the surface film.
- A parachute BWO or similar dry in sizes that are often 18 or smaller.
Fine tippet and a careful, drag-free drift matter more here than the exact pattern.
Caddis and Other Late Hatches
Some rivers have larger fall caddis, often called October caddis (see fly fishing in October), which can bring larger, orange-bodied dry flies and pupa patterns into play. Not every river has them. A general-purpose Elk Hair Caddis in orange or tan is a reasonable option where they are present. Check local reports before relying on them.
Streamers
Cooler water and pre-spawn or post-spawn aggression can make autumn a good time to fish streamers, particularly for brown trout. Woolly Buggers, sculpin patterns and baitfish imitations are common choices. Cloudy days and low light often help. Read minnow fly patterns for trout for colors, sizes and retrieves.
Egg Patterns and Spawning Fish
When trout or salmon spawn, other trout often feed on loose eggs, so egg patterns and similar flies can be productive in some rivers. Please be responsible:
- Avoid wading through spawning beds, called redds, which are often clean, lighter patches of gravel.
- Avoid targeting fish that are actively spawning.
- Check local regulations, since some waters are closed or restricted in fall to protect spawners.
Terrestrials Early in the Season
Early autumn can still offer ants, beetles and hoppers until the first hard frosts. A foam or hair-wing terrestrial fished along banks can be a fun choice on warm days.
Heading Toward Winter
As water gets colder, trout often hold in slower, deeper runs and feed less aggressively. Smaller nymphs and midge patterns become more important; see midge fly fishing. For a broader overview, our must-have trout flies guide helps cover the basics.
FAQ
What flies should I use in October?
Many anglers start with a BWO nymph or dry, an Elk Hair Caddis, a Woolly Bugger and, where appropriate and legal, an egg pattern. Local conditions decide the final choice.
What flies are good for trout in winter?
Small nymphs and midge patterns, fished slowly in deeper, slower water, are common choices.
What are the best flies for trout fishing overall?
There is no single list. A balanced mix of dries, nymphs and streamers is a good start, as outlined in our first fly box guide.