Looking for the best trout flies for July on the Welsh Dee and other Northwest Freestone rivers? Drawing on more than two decades of fishing records, this guide reveals the eight fly patterns I rely on every summer to catch wild brown trout and grayling. You’ll learn which flies consistently produce fish, when to fish wet flies, dry flies or nymphs, and how to adapt your fly selection to changing river and weather conditions on one of the UK’s finest rivers.
Introduction
July is one of my favourite months for fly fishing the Welsh Dee. Long evenings, prolific insect life and active wild brown trout can produce outstanding sport, but summer fishing also presents its own challenges. Low, clear water, bright sunshine and increasingly selective fish mean that choosing the right fly often makes the difference between a memorable day and a frustrating one.
After recording catches and conditions over many years, I’ve found that success rarely comes from carrying hundreds of fly patterns. Instead, a carefully selected box of proven summer trout flies consistently outperforms constant experimentation. The eight flies featured in this guide have earned their place through years of success on the Welsh Dee and remain my first choice whenever I fish the river in July. Whether you’re targeting wild brown trout, grayling or simply planning your next fly fishing trip to North Wales, these patterns provide a reliable foundation for summer success.
Key Takeaways
- Three wet flies account for around 75% of my July catches, making them the ideal starting point when fish aren’t showing a clear preference.
- The Weighted March Brown (WMB) is my single most productive all-round fly for July and the first pattern I’d recommend to any angler fishing the Welsh Dee.
- Match the hatch whenever fish are rising, using simple dry flies such as the Grey Duster, Griffith’s Gnat and Black Gnat.
- During bright midday conditions, switching to small tungsten-beaded nymphs in fast, shaded water can turn a slow session into a productive one.
- Focus your efforts around fast runs, pool tails, weed beds, boulders and shaded lies, where trout and grayling are most likely to hold during summer conditions.
Top Flies for July Trout and Grayling
If you are new to fly fishing, these flies will help you catch trout and grayling on the Welsh Dee. Also, they should be helpful to the more seasoned anglers who plan to fish the Welsh Dee for the first time.
Before we dive in…
It’s worth highlighting the natural flies that are likely to be seen on the Welsh Dee in July.
Upwinged flies:
- Iron Blue Dun
- Blue-winged Olive
- Yellow May Dun
- Yellow Sally
- Small Dark Olive
- Pale Watery Dun
- Medium Olive
Sedges :
- Black sedge
- Cinnamon sedge
- Yellow Sedge
- Welshman’s Button
Others :
- Black Gnat
- Midges
- Daddy Longlegs
- Caenis
Based on the variety of natural flies, you’d think to catch trout and grayling that an extensive selection of artificial fly patterns would be required.
However, after analysing my detailed fishing log, I was surprised that selecting the best-performing flies for July wasn’t too difficult, because….
75% of all the fish I have caught in July were on three wet flies:
My top 3 performing flies for July on the Welsh Dee
- 30% on WMB #12
- 25% on Pearl-ribbed March Brown spider #14
- 20% on Black Hopper #14
Therefore, if it’s not clear what trout and grayling are feeding on, my recommendation would be to start with a three-fly cast on a 3lb copolymer (point: size 12,
If you are new to fly fishing and want to fish just one fly on the Welsh Dee in July. Then it would have to be a…
WMB (size 12 or 14)
So, what is a WMB?
It’s nothing fancy…
It’s just a weighted March Brown Spider pattern, but it is special because it’s a great all-rounder.
WMB (weighted March Brown)
- Hook: #12 Kamasan B170
- Thread: Rusty orange UNI 8/0
- Underbody: Fine lead wire
- Body: Hare’s ears fibres of varying length & colour
- Rib: Fine oval gold tinsel
- Hackle: Brown partridge neck feather
I came across this fly pattern in the May 1997 edition of Trout & Salmon magazine. In an article entitled ‘Make Mine A WMB’ by Bob Nunn. Who claimed…
“One fly is usually all you need for river fishing”
Intrigued by the article, I tied a few and started experimenting with it on the Welsh Dee and, for over 20 years, I’ve not been without a few in my fly box.
It also works well on the other northwest river I fish, where it has been the downfall of plenty of trout and grayling.
In addition to the many trout and grayling, I’ve caught quite a few Welsh Dee sea trout during the day on the WMB.
Pearl-ribbed March Brown Spider
- Hook: Kamasan B170 #14
- Thread: Tan UNI-Thread 8/0
- Body: Fox squirrel dubbing
- Rib: Uni Pearl Mylar (1/32)
- Hackle: Brown partridge neck feather
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
Where are the best places to fish wet flies in July?
When the Welsh Dee is at its summer level, it’s best to focus your fly fishing efforts in the following sections of the river:
- 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
Now let’s consider what to do if the above fails to catch trout and grayling.
Dry flies for July on the Welsh Dee:
When trout and grayling are preoccupied with taking dry flies, the best approach is to try and match the hatch.
If you cannot match the hatch, then tying a small Grey Duster dry fly onto a tapered leader should fool a few trout and/or grayling.
Grey Duster
- Hook: HENDS BL354 (#14 to 20)
- Thread: Grey 8/0
- Tail: Badger cock fibres
- Post: Single CDC feather
- Body: Rabbit underfur
- Hackle: Badger cock
Often during July, you will spot fish sipping something indistinguishable from the surface. When this happens, I find it best to try either a small Griffith’s Gnat or a Black Gnat dry fly pattern.
Griffith’s Gnat
- Hook: Kamasan B170 size 18
- Thread: Black UNI 8/0
- Body: Peacock herl
- Hackle: Palmered Grizzle cock
Black Gnat
- Hook – Kamasan B100 (#16 to 20)
- Thread – Black 8/0
- Wing post – Cream Antron yarn
- Body – Black 8/0 head
- Thorax – black dubbing
- Hackle – black cock
To help track these small flies on the river, it’s sometimes beneficial to fish them behind a larger sight fly, such as an Elk Hair Caddis.
On bright sunny days when the river is low and crystal clear, 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 July:
Euro / Czech nymphing isn’t everyone’s cup of tea…
However, it’s worth having in your armoury because when trout and grayling are feeding on the riverbed, it’s the best way to catch them.
Consider the following scenario…
After great sport on wet or dry flies in the morning, the river turns dead from midday until the sun starts to set
How do you fill in the hours until the evening rises?
- Go to the pub for a long lunch and a rest, which is not a bad shout.
Or have your lunch on the riverbank and…
- Search for where the fish have gone.
If it’s the latter, you will need to switch to nymphing the fast runs and deep shady pockets of water, where you will often find trout and grayling feeding on small nymphs.
Over the years of practice, I’ve found that fishing a couple of small nymphs (#16 or #18) above a heavy (ca. 4-5mm) tungsten bead point nymph works well.
Normally, one of the following simple nymphs (size 16 or 18) will catch trout and grayling…
- Pheasant tail nymph with a 1.5mm copper tungsten bead
- Peacock quill nymph with a 1.5mm copper tungsten bead
- Red nymph with a 1.5mm gold tungsten bead
Pheasant tail nymph
- Hook – HENDS BL354 #16 & 18
- Bead – 1.5 tungsten (copper, neutral)
- Thread – Rusty Orange UNI-Thread 8/0
- Tail – Ginger cock
- Body – Pheasant tail fibres
- Rib – Fine copper wire
- Thorax – Hare’s Ear dubbing
Peacock Quill nymph
- Hook – Kamasan B100 size 16 or 18
- Bead – 1.5 tungsten bead
- Tail – Coq De Leon fibres
- Thread – Grey UNI-Thread 8/0
- Body – Stripped peacock quill
- Thorax – Light Hare’s Ear dubbing
Black nymph
- Hook – HENDS jig #16 & 18
- Bead – 1.5 black tungsten
- Body – Black UNI-Thread 8/0
- Tag – Pink thread 8/0
- Thorax – Black Glister dubbing
Flies for July Conclusion
July rewards anglers who keep their approach simple and fish with confidence. While river levels, weather and insect hatches can vary from day to day, the 8 flies for July in this guide have consistently produced wild brown trout and grayling on the Welsh Dee over many seasons.
Rather than constantly changing flies, concentrate on fishing these proven patterns well, adapting your presentation to the prevailing conditions and targeting likely holding water.
No two days on the Dee are ever the same, and that’s part of what makes this remarkable river such a rewarding place to fish. Keep notes on what works, build confidence in a small selection of reliable flies, and you’ll soon develop your own favourites alongside those I’ve shared here.
If you’re planning a trip to the Dee, be sure to explore my other monthly fly recommendations and river guides to help you choose the right patterns throughout the season.
I’ve listed a selection of additional blog posts that you will find helpful…
- Matching the Hatch – A mobile friendly fly guide
- How to catch grayling in the heat of summer on the Welsh Dee
- July is the time for beautiful sea trout
- July fishing report from the banks of the beautiful Welsh Dee
Tight Lines, and I hope those flies for July bring you as much success as they’ve brought me over the years.
Also, if you’re interested in fishing the Welsh Dee, it has some good Day Ticket water for fly fishing.
Great article as usual Andrew , keep them coming.
Fished the Dee yesterday using the wet fly team you suggested for July. Had 4 on the black hopper and one on the pearly MB. Thanks for your efforts in putting these articles together. Much appreciated.
Many thanks Andrew, most useful articles that I look forward to receiving.
Hi Paul,
Great to hear you are finding them interesting.
Thanks for the feedback. Tight lines, Andrew
WMB
you say primrose thread but show one with a RED head ! Which should it be?
About to try them out on the Dee at Llangollen next week.. Thanks for all your advice and the best of blogs.
Hi Rodney,
It should be rusty orange thread – I’ve corrected the post now.
Good luck, Andrew
Hi Andrew, new to all this so lots to learn. Hoping to fish Bangor on Dee next week. With the WMB do you buy a fly like that or just weight it yourself?
Hi Jack,
I tie them myself. Not come across weighted versions for sale.
Good luck at BoD.
Andrew