12 Great Flies for September Trout and Grayling Fishing

September marks the arrival of autumn, with longer nights and the closing of the brown trout season at month-end. To help you make the most of this fishing season, I’m excited to share…

12 great flies for September.

These fly patterns not only excel in catching trout but are also highly effective for grayling fishing on the scenic Welsh Dee.

Whether you’re a novice or a seasoned angler, these insights are bound to enhance your September fishing experience.

Understanding my selection of flies for September

Before diving into the specifics of my fly recommendations, it’s essential to understand the natural flies prevalent in September on UK rivers. These include the following up-wing flies, sedges and terrestrials:

Streamlined Fly Selection

After meticulously reviewing my fly fishing log from the past five years, I’ve identified the three flies that consistently outperformed the rest in September, accounting for a…

Despite the variety of natural flies, I’ve simplified the selection process.

remarkable 65% of my trout and grayling catches:

• 30% on Black Hopper (#14)
• 20% on March Brown Spider (#16 & 14)
• 15% on Pearl-ribbed March Brown Spider (#16 & 14)

There’s a bias in my September fly selection because most of my trout and grayling fishing has been when the river was close to its summer level. Whereas, when the Welsh Dee was in spate, I was often fly fishing for salmon.

If I’d spent time fishing for trout and grayling when the river was in spate, nymph patterns would…

knock the wet flies off their top spot.

My Go-To three-fly cast for September

If you’re unsure about what flies the fish are taking, I recommend starting with a versatile three-fly cast on 3lb copolymer:

• Point: #14 Black Hopper
• Middle Dropper: #14 March Brown Spider
• Top Dropper: #16 Pearl-ribbed March Brown Spider

These flies have consistently produced results for me in September and should serve you well.

Single fly cast selection for September:

If you prefer fishing with a single fly in September, your selection should depend on two factors:

• surface-feeding activity, and
• water conditions.

When trout and grayling are actively feeding on surface flies, March Brown Spider patterns in sizes #14 and #16 are hard to beat. Their consistent success makes them an ideal choice for targeting rising fish in streamy, clear water.

March Brown Spider

• Hook:     Kamasan B170 #14 & 16
• Thread:   Waxed orange UNI 8/0
• Body:       Hare’s ears fibres of varying length & colour
• Rib:          Medium gold wire
• Hackle:    Brown partridge neck feather

Tying Instructions

Pearl-ribbed March Brown Spider

• Hook:     Kamasan B170 #14 & 16
• Thread:   Waxed orange UNI 8/0
• Body:       Hare’s ears fibres of varying length & colour
• Rib:          Pear Mylar fine
• Hackle:    Brown partridge neck feather

Tying Instructions

Next, When fish are not actively feeding at the surface, fishing a Black Hopper just below it is often an excellent choice to tempt both trout and grayling.

Black Hopper

• Hook:      Kamasan B170 size 14
• Thread:   Black UNI-Thread 8/0
• Body: Black seal fur substitute
• Rib:          Uni Pearl Mylar (1/32)
• Legs:       Black pheasant tail
• Hackle:   Black (natural) hen

Tying Instructions

Additional wet fly patterns for September: 

Two other wet flies that have featured prominently in my fishing log are the Treacle Parkin (red-tagged version) and the Peter Ross. These flies have unique qualities and can be valuable additions to your fly box.

The Treacle Parkin is best fished on the top dropper of a three-fly cast and has been the downfall of many grayling on the Welsh Dee.

Treacle Parkin (red-tag)

• Hook:    Kamasan B170 #16
• Body:     Brown UNI-Thread 8/0
• Tag:       Red UNI-Thread 8/0
• Body: Peacock herl
• Hackle:  Brown hen

The Peter Ross is a great point fly for brown trout feeding on fry in the slow pools. In addition, it will often entice the sea trout on dull days.

Peter Ross

• Hook:    Kamasan B170 #14 & #12
• Thread: Black UNI-Thread 8/0
• Tag:       Golden Pheasant Tippet
• Body: Silver tinsel & claret dubbing
• Rib: Fine silver wire
• Wing: Teal flank feather
• Hackle:  Black hen

Wet fly fishing in September

When the river is close to its summer level, I find it best to focus your wet fly fishing efforts on the following sections of the river during the day:

• the fast water leading into deep pools; 
• shady areas, particularly under overhanging trees & bushes;
• alongside weed beds, large rocks, ledges, and snags;
• the tails of pools, especially in the evening.

However, in the evening, the slow sections of pools often come alive with rising trout and grayling and thus should not be ignored.

Now let’s consider what to do if the above flies for September fail to catch trout and grayling.

Trout and grayling dry flies for September:

When trout and grayling are preoccupied with taking dry flies, the best approach is to try and match the hatch. 

Usually, a rough fly match in general size and colour will suffice in September. Many of the natural flies you will encounter are olives. Therefore, an olive dry fly pattern in various sizes and shades will often suffice.

Over the years, a small F-fly in various colours (black, grey, olive, etc.) has proven to be one of the best dry flies for September on the Welsh Dee and River Ribble.

F-fly in various colours

• Hook:   Kamasan B170 #16 & 18
• Thread: Black UNI 8/0
• Body: Fine dubbing (black, olive etc.)
• Wing: 3 CDC feathers

Tying Instructions

For trout and grayling feeding on tiny flies, it is necessary to go smaller, and #20 or 22 fly usually does the business.

In poor light, following small dry flies during the drift is difficult. Therefore, I will use a dry fly fishing set-up where the small fly is trailing (ca. 3ft) behind a large sight fly (often an Elk hair caddis).

Elk hair caddis

• Hook:      Kamasan B170 #16 to 12
• Thread:  Burnt orange UNI 8/0
• Tag: Cream Antron
• Body:      Fox squirrel dubbing
• Rib: Gold wire
• Wing:      Natural Elk hair

Tying Instructions

On warm evenings in September, the Elk hair caddis is a good pattern because it catches lots of trout and grayling; particularly when they are feeding on sedges hatching at nightfall.

As the light fades it becomes difficult to see the rises. At this point, try fishing this caddis across and downriver so that it skates on the surface. This method has caught me some…

smashing trout, grayling and sea trout.

On bright sunny days, you might find that dry and wet fly fishing fails to catch fish. So, let’s now consider what you might do to avoid a blank.

Nymph flies for September success:

Euro / Czech nymphing is not everyone’s cup of tea, but it’s worth having in your armoury for when Autumn arrives.

In September, when trout and grayling are feeding on the riverbed and not rising to flies higher in the water column…

Nymphing can produce excellent results.

In clear rivers, fishing size 16 or 18 nymphs above a heavy tungsten bead (3+ mm) nymph has been fruitful

My recommended nymph patterns for clear water include:

Claret nymph

• Hook:  HENDS BL345 #16 & 18
• Bead:    1.5mm tungsten purple
• Thread: claret UNI-Thread 8/0
• Body:     claret UNI-Thread 8/0
• Thorax: Mole fur
• Wing case:   Pearl Mylar 1/8”

TB Quill nymph

• Hook:    Hends #16 & 18
• Bead:     1.5 tungsten
• Thread:  Red UNI-Thread 8/0
• Tail: Coq de Leon fibres
• Body:      Stripped peacock quill
• Thorax:   Hare’s ear dubbing  

For coloured water, however, I opt for fishing nymphs with some a touch of “Bling” and often find success nymphing with the following flies:

Olive Tungsten Jig-back

• Hook:  Hends BL154 (#12)
• Weight:   copper XL-tungsten jig-back
• Thread: orange UNI-Thread 8/0
• Body: stretched clear latex
• Rib: brown wire
• Throat: Pink nail varnish
• Coating: UV – Varnish

Orange collar PTN

• Hook: Hends BL154 (#12 & 14)
• Bead:  metallic orange tungsten (3-4mm)
• Thread: orange UNI-Thread 8/0
• Body: Pheasant tail fibre
• Rib: gold wire
• Hackle: CDC feather
• Collar: Veniard glister sparkle orange dubbing

Streamer fishing for trout in September.

As autumn progresses, brown trout often feed on fry, especially in coloured water.

Streamer fishing can be highly productive during these conditions, particularly when ‘normal’ fly fishing methods might fail.

Occasionally I’ve caught brown trout on the Welsh Dee with small half-digested grayling protruding from their mouth. That led me to try Minkie fly patterns.

Consider using patterns like the Grayling Streamer, which has proven successful in enticing brown trout in these situations.

Streamer – Grayling fry

• Hook: Kamasan KB800 #10
• Thread: Black 8/0
• Body: Pearl Glister dubbing
• Wing: Grey zonker strip
• Eyes: 4 mm Epoxy
• Head: Clear UV resin

Streamer fishing with a fast-sinking line on a flooded Welsh Dee has saved the day on numerous occasions.

Check out the following post for information on fly fishing for grayling during autumn:

• Grayling fly fishing in Autumn with a focus on the beautiful Welsh Dee

Also, you might find these posts on exploits on the Welsh Dee in September interesting…

• Game fishing in September on the beautiful Welsh Dee
• September fishing report: A ‘Grand Slam’ on the amazing Welsh Dee
• Fishing for reliable grayling on the wonderful Welsh Dee

The above fly selection is reliable for catching trout and grayling in September. Thus, a great starting point for a newcomer to fishing the Welsh Dee and other rivers in the Northwest.

There are some good day ticket beats on the Welsh Dee to experience some tout and world-class grayling fishing.

Finally, I hope you found this post interesting, and it would be great to hear about your best trout flies for September.