How to Fly Fish BC Stillwaters in September

Fred Helmer
Sep 16, 2025
2 min read

Blobs can be one of the most effective flies in the Fall.

September is one of the best months for stillwater fly fishing. As air and water temperatures drop, trout become more active and start feeding heavily in preparation for winter. Here’s how to make the most of your time on the water this month.

1. Watch the Water Temperature

Target range: 15–16°C (60–62°F).
Cooler water boosts trout activity, so keep a thermometer handy.

2. Match the Food Sources

Trout diets shift in early Fall. Stock your fly box with:

Water boatmen & backswimmers – Fish these on sunny, calm days when flights occur. Look for “raindrop” splashes and swirling rises as trout feed aggressively on bugs hitting the surface and swimming up from the bottom.
Leeches – A staple food source as trout move shallower. Fish them slowly with steady retrieves or under indicators.
Scuds (shrimp) – Productive in weedy areas and along drop-offs.A slow retrieve or under an indicator.
Daphnia (blobs) – Effective when trout school up and feed on plankton. Sometimes fish are just hungry and will eat blobs in the strangest places.
Chironomids – Be alert for late-season hatches; trout may switch focus quickly.

3. Adjust Your Depth

Early September: Focus deeper (up to 6 metres / 18 feet).
As temperatures drop further, move shallower, where trout chase leeches, damselfly nymphs, dragonfly nymphs, and scuds.

4. Presentation Tips

Vary retrieves: short strips, long pulls, or hand-twist retrieves until you find what triggers strikes.
Use intermediate or sinking lines to cover key depths.
Be ready to switch flies quickly when you see fish feeding—especially during boatman and backswimmer activity.

5. Stay Alert for Visual Cues

Rising fish leaving swirl marks.
“Raindrop” dimples on the surface (a sign of boatmen falling onto the water).
Sudden feeding flurries near drop-offs or weed edges.

With the right approach, September can deliver some of the most consistent stillwater fishing of the year. Think cooler water, varied food sources, and trout that are finally hungry again—perfect conditions for fly anglers.